# The LearningOnline Network with CAPA
# Tags Default Definition Module 
#
# $Id: londefdef.pm,v 1.390.2.2 2008/10/02 18:09:38 raeburn Exp $
# 
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# LON-CAPA is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
## Copyright for TtHfunc and TtMfunc by Ian Hutchinson. 
# TtHfunc and TtMfunc (the "Code") may be compiled and linked into 
# binary executable programs or libraries distributed by the 
# Michigan State University (the "Licensee"), but any binaries so 
# distributed are hereby licensed only for use in the context
# of a program or computational system for which the Licensee is the 
# primary author or distributor, and which performs substantial 
# additional tasks beyond the translation of (La)TeX into HTML.
# The C source of the Code may not be distributed by the Licensee
# to any other parties under any circumstances.
#

package Apache::londefdef; 

use Apache::lonnet;
use strict;
use Apache::lonxml;
use Apache::File();
use Image::Magick;
use Apache::lonmenu();
use Apache::lonmeta();
use Apache::lonlocal;
use Apache::Constants qw(:common);
use File::Basename;
use LONCAPA();
# use Data::Dumper;

BEGIN {

    &Apache::lonxml::register('Apache::londefdef',('a','abbr','acronym','accessrule','address','allow','applet','area','b','base','basefont','bgo','bgsound','big','blink','blockquote','blankspace','body','br','button','caption','center','cite','code','col','colgroup','dd','del','dfn','dir','div','dl','dt','em','embed','externallink','fieldset','font','form','frame','frameset','h1','h2','h3','h4','h5','h6','head','hr','html','i','iframe','img','input','ins','insert','isindex','kbd','keygen','label','layer','legend','li','link','m','map','marquee','menu','meta','multicol','nobr','noembed','noframes','nolayer','noscript','object','ol','optgroup','option','output','p','param','pre','q','s','samp','select','server','small','spacer','span','strike','strong','sub','sup','table','tbody','td','textarea','tfoot','th','thead','title','tr','tt','tthoption','u','ul','var','wbr','hideweboutput'));

}

#
#   Dumps all elements of the table structure.
#   Need this 'cause evidently when given an array, Data::Dumper only seems
#   to dump element 0.
#
#sub debug_dump_table {
#    my $lastrow = $#Apache::londefdef::table;
#    &Apache::lonnet::logthis("Dumping table:  Last row index: $lastrow");
#    my $row;
#    for ($row =0; $row <= $lastrow; $row++ ) {
#	my $text = Dumper($Apache::londefdef::table[$row]);
#	&Apache::lonnet::logthis("table [ $row ]".$text);
#    }
#}
sub initialize_londefdef {
    $Apache::londefdef::TD_redirection=0;
    @Apache::londefdef::table = ();
    $Apache::londefdef::select=0;
    undef(@Apache::londefdef::description);
    @Apache::londefdef::DD=(0);
    @Apache::londefdef::DT=(0);
    @Apache::londefdef::seenDT=(0);
    $Apache::londefdef::list_index=0;
    undef($Apache::londefdef::head);
    undef($Apache::londefdef::title);
}

#======================= TAG SUBROUTINES =====================
#-- <output>
sub start_output {
    my ($target) = @_;
    if ($target eq 'meta') { $Apache::lonxml::metamode--; }
    return '';
}
sub end_output {
    my ($target) = @_;
    if ($target eq 'meta') { $Apache::lonxml::metamode++; }
    return '';
}
#-- <m> tag
sub start_m {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
    my $currentstring = '';
    my $inside = &Apache::lonxml::get_all_text_unbalanced("/m",$parser);
    if ($target eq 'web' || $target eq 'analyze') {
	&Apache::lonxml::debug("M is starting with:$inside:");
	my $eval=&Apache::lonxml::get_param('eval',$parstack,$safeeval);
	if ($eval eq 'on') {
	    $inside=&Apache::run::evaluate($inside,$safeeval,$$parstack[-1]);
	    #&Apache::lonxml::debug("M is evaulated to:$inside:");
	}
	my $tex = $inside;
	my $display=&Apache::lonxml::get_param('display',$parstack,$safeeval);
	$currentstring = &Apache::lontexconvert::converted(\$inside,$display);
	if ($Apache::lontexconvert::errorstring) {
	    my $errormsg='<pre>'.&HTML::Entities::encode($Apache::lontexconvert::errorstring,'<>&"').'</pre> occurred while attempting to convert this TeX: <pre>';
	    $tex = &HTML::Entities::encode($tex,'<>&"');
	    my ($linenumber) =
		($Apache::lontexconvert::errorstring =~ /Line (\d+)/);
	    if (defined($linenumber)) {
		my @tex=split("\n",$tex);
		$tex[$linenumber]='<b><font color="red">'.
		    $tex[$linenumber].'</font></b>';
		$tex=join("\n",@tex);
	    }
	    &Apache::lonxml::warning($errormsg.$tex.'</pre>');
	    $Apache::lontexconvert::errorstring='';
	}
	#&Apache::lonxml::debug("M is ends with:$currentstring:");
	$Apache::lonxml::post_evaluate=0;
    } elsif ($target eq 'tex') {

	$currentstring = $inside;
	my $eval=&Apache::lonxml::get_param('eval',$parstack,$safeeval);
	if ($eval eq 'on') {
	    $currentstring=&Apache::run::evaluate($currentstring,$safeeval,$$parstack[-1]);
	}
	if ($currentstring=~/^(\s*\\\\\s*)*$/) {$currentstring = ' \vskip 0 mm ';}
	# detect simple math mode entry exits, and convert them
        # to use \ensuremath ... unless there's a \verb inside.
	if (! ($currentstring=~/\\verb/)) {
	    if ($currentstring=~/^\s*\$[^\$].*[^\$]\$\s*$/) {
		$currentstring=~s/^(\s*)\$/$1/;
		$currentstring=~s/\$(\s*)$/$1/;
		$currentstring='\ensuremath{'.$currentstring.'}';
	    }
	}
	$Apache::lonxml::post_evaluate=0;
    }
    return $currentstring;
}

sub end_m {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'tex') {
	$currentstring = "";
    }
    return $currentstring;
}

sub start_tthoption {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
    my $result;
    if ($target eq 'web' || $target eq 'webgrade') {
	my $inside = &Apache::lonxml::get_all_text("/tthoption",$parser,
						   $style);
	$inside=~s/^\s*//;
	if ($env{'browser.mathml'}) {
	    &tth::ttmoptions($inside);
	} else {
	    &tth::tthoptions($inside);
	}
    }
    return $result;
}

sub end_tthoption {
    my ($target,$token) = @_;
    my $result;
    return $result;
}

#-- <html> tag (end tag optional)
sub start_html {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'edit' || $target eq 'webgrade' ) {
	# start_body() takes care of emitting the <html> 
    } elsif ($target eq 'tex') {
	$currentstring .= 
	    '\documentclass[letterpaper,twoside]{article}\raggedbottom';
	if (($env{'form.latex_type'}=~'batchmode') ||
            (!$env{'request.role.adv'})) {$currentstring .='\batchmode';} 
	$currentstring .= '\newcommand{\keephidden}[1]{}'.
                          '\renewcommand{\deg}{$^{\circ}$}'.
			  '\usepackage{multirow}'.
                          '\usepackage{longtable}'.
                          '\usepackage{textcomp}'.
                          '\usepackage{makeidx}'.
                          '\usepackage[dvips]{graphicx}'.
			  '\usepackage{wrapfig}'.
			  '\usepackage{picins}'.
			  '\usepackage[T1]{fontenc}'."\n".
                          '\usepackage{lmodern}'."\n".
			  '\usepackage[postscript]{ucs}'."\n".
			  '\usepackage[utf8x]{inputenc}'."\n".
			  '\usepackage{pifont}' ."\n".
			  '\usepackage{latexsym}'."\n".
                          '\usepackage{epsfig}'.
                          '\usepackage{calc}'.
                          '\usepackage{amsmath}'.
                          '\usepackage{amssymb}'.
                          '\usepackage{amsfonts}'.
                          '\usepackage{amsthm}'.
                          '\usepackage{amscd}'.
                          '\newenvironment{choicelist}{\begin{list}{}{\setlength{\rightmargin}{0in}\setlength{\leftmargin}{0.13in}\setlength{\topsep}{0.05in}\setlength{\itemsep}{0.022in}\setlength{\parsep}{0in}\setlength{\belowdisplayskip}{0.04in}\setlength{\abovedisplayskip}{0.05in}\setlength{\abovedisplayshortskip}{-0.04in}\setlength{\belowdisplayshortskip}{0.04in}}}{\end{list}}'.
                          '\renewenvironment{theindex}{\begin{list}{}{{\vskip 1mm \noindent \large\textbf{Index}} \newline \setlength{\rightmargin}{0in}\setlength{\leftmargin}{0.13in}\setlength{\topsep}{0.01in}\setlength{\itemsep}{0.1in}\setlength{\parsep}{-0.02in}\setlength{\belowdisplayskip}{0.01in}\setlength{\abovedisplayskip}{0.01in}\setlength{\abovedisplayshortskip}{-0.04in}\setlength{\belowdisplayshortskip}{0.01in}}}{\end{list}}';
    }
    return $currentstring;
}

sub end_html {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	# end_body takes care of the </html>
    }
    return $currentstring;
}

#-- <head> tag (end tag optional)
sub start_head {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	&Apache::lonxml::startredirection();
    } 
    return $currentstring;
}

sub end_head {
    my ($target,$token) = @_;
    my $currentstring = '';
    if (($target eq 'web'      && $env{'request.state'} eq 'published') ||
	($target eq 'webgrade' && $env{'request.state'} eq 'published')) {
	# in case there is a </head> but no <head>
	if ($Apache::lonxml::redirection) {
	    $Apache::londefdef::head = &Apache::lonxml::endredirection();
	}
    } 
    return $currentstring;
}

#-- <map> tag (end tag required)
sub start_map {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_map {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <select> tag (end tag required)
sub start_select {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    }  elsif ($target eq 'tex') {
	$Apache::londefdef::select=0;
    }
    return $currentstring;
}

sub end_select {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <option> tag (end tag optional)
sub start_option {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } elsif ($target eq 'tex') {
	$Apache::londefdef::select++;
	if ($Apache::londefdef::select == 1) {
	    $currentstring='\noindent\fbox{'.&Apache::lonxml::get_param('value',$parstack,$safeeval).'}\keephidden{';
	} else {
	    $currentstring='\keephidden{';
	}
    }
    return $currentstring;
}

sub end_option {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    }  elsif ($target eq 'tex') {
	$currentstring='}';
    }
    return $currentstring;
}

#-- <input> tag (end tag forbidden)
sub start_input {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_input {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <textarea> tag (end tag required)
sub start_textarea {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_textarea {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <form> tag (end tag required)
sub start_form {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_form {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <title> tag (end tag required)
sub start_title {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$Apache::londefdef::title = 
	    &Apache::lonxml::get_all_text('/title',$parser,$style);
    } elsif ($target eq 'tex') {
	$currentstring .= '\keephidden{Title of the document:  ' 
    }
    if ($target eq 'meta') {
	$currentstring='<title>';
	&start_output($target);
    }
    return $currentstring;
}

sub end_title {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	# start_title takes care of swallowing the title
    } elsif ($target eq 'tex') {
	$currentstring .= '}';
    }  
    if ($target eq 'meta') {
	&end_output($target);
	$currentstring='</title>';
    } 
    return $currentstring;
}

#-- <meta> tag (end tag forbidden)
sub start_meta {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	my $args='';
	if ( $#$parstack > -1 ) { $args=$$parstack[$#$parstack]; }
	if ($args eq '') {
	    &Apache::lonxml::get_all_text("/meta",$parser,$style);
	} else {
	    $currentstring = $token->[4];
	}
    } elsif ($target eq 'meta') {
	unless (&Apache::lonxml::get_param
		('http-equiv',$parstack,$safeeval,undef,1)) {
	    my $name=$token->[2]->{'name'};
	    $name=~tr/A-Z/a-z/;
	    $name=~s/\s/\_/gs;
	    $name=~s/\W//gs;
	    if ($name) {
		$currentstring='<'.$name;
                 my $display=&Apache::lonxml::get_param
		('display',$parstack,$safeeval,undef,1);
                if ($display) {
                    $display=~s/\"/\'/g;
		    $currentstring.=' display="'.$display.'"';
                }
		$currentstring.='>'.
		    &Apache::lonxml::get_param
			('content',$parstack,$safeeval,undef,1).
			'</'.$name.'>';
	    }
            my $display=&Apache::lonxml::get_param
		('display',$parstack,$safeeval,undef,1);
            if ($display) {
		$display=&HTML::Entities::encode($display,'<>&"');
		$currentstring.='<'.$name.'.display>'.$display.
                               '</'.$name.'.display>';
            }
	}
    } elsif ($target eq 'tex') {
	my $content=&Apache::lonxml::get_param('content',$parstack,$safeeval);
	my $name=&Apache::lonxml::get_param('name',$parstack,$safeeval);
	if ((not defined $content) && (not defined $name)) {
	    &Apache::lonxml::startredirection();
	}
    } elsif ($target eq 'edit') {
	$currentstring .= &Apache::edit::tag_start($target,$token);
	$currentstring .= &Apache::edit::text_arg('Name:','name',$token,30);
	$currentstring .= &Apache::edit::text_arg('Content:','content',$token,70);
	$currentstring .= &Apache::edit::end_row();
    } elsif ($target eq 'modified') {
	my $constructtag =
	    &Apache::edit::get_new_args($token,$parstack,$safeeval,
					'name','content');
	if ($constructtag) { $currentstring = &Apache::edit::rebuild_tag($token); }
    }
    return $currentstring;
}

sub end_meta {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	my $args='';
	if ( $#$parstack > -1 ) { $args=$$parstack[$#$parstack]; }
	if ($args ne '') {
	    $currentstring = $token->[4];
	}
    } elsif ($target eq 'tex') {
	my $content=&Apache::lonxml::get_param('content',$parstack,$safeeval);
	my $name=&Apache::lonxml::get_param('name',$parstack,$safeeval);
	if ((not defined $content) && (not defined $name)) {
	    &Apache::lonxml::endredirection();
	}
    }
    return $currentstring;
}

sub insert_meta {
    return '
    <meta />';
}

# accessrule
sub start_accessrule {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
    my $currentstring = '';
    my $eff  =&Apache::lonxml::get_param('effect',$parstack,$safeeval,undef,1);
    my $realm=&Apache::lonxml::get_param('realm', $parstack,$safeeval,undef,1);
    my $role =&Apache::lonxml::get_param('role',  $parstack,$safeeval,undef,1);
    my $type =&Apache::lonxml::get_param('type',  $parstack,$safeeval,undef,1);

    my ($dom,$crs,$sec,$separator);
    if ($type eq 'user') {
	($dom,$crs,$sec)=split(m{/},$realm);
	$crs = &LONCAPA::clean_username($crs);
	$separator = '/';
    } else {
	($dom,$crs,$sec)=split(/\_/,$realm);
	$crs = &LONCAPA::clean_courseid($crs);
	$separator = '_';
    }
    $dom = &LONCAPA::clean_domain($dom);

    $sec =~s/\W//;
    $realm = $dom;
    if ($crs =~ /\S/) { $realm .= $separator.$crs; }
    if ($sec =~ /\S/) { $realm .= $separator.$sec; }
    $role=~s/\W//g;

    if ($target eq 'web') {
	my $args='';
	if ( $#$parstack > -1 ) { $args=$$parstack[$#$parstack]; }
	if ($args eq '') {
	    &Apache::lonxml::get_all_text("/accessrule",$parser,$style);
	} else {
	    $currentstring = $token->[4];
	}
    }
    if ($target eq 'meta') {
	$currentstring='<rule>'.$eff.':'.$realm.':'.$role.':'.$type.'</rule>';
    }
    return $currentstring;
}

sub end_accessrule {
    my ($target,$token,$tagstack,$parstack,$parser) = @_;
    my $currentstring = '';
    if ($target eq 'web') {
	my $args='';
	if ( $#$parstack > -1 ) { $args=$$parstack[$#$parstack]; }
	if ($args ne '') {
	    $currentstring = $token->[4];
	}
    } 
    return $currentstring;
}

sub generate_css_links {
    my $links;
    my $css_href = &Apache::lonnet::EXT('resource.0.cssfile');
    if ($css_href =~ /\S/) {
	&Apache::lonxml::extlink($css_href);
	$links .= 
	    '<link rel="stylesheet" type="text/css" href="'.$css_href.'" />';
    }
    return $links;
}

#-- <body> tag (end tag required)
sub start_body {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';

    if ($target eq 'web' || $target eq 'webgrade') {
	if ($Apache::lonhomework::parsing_a_problem) {
	    &Apache::lonxml::warning("<body> tag found inside of <problem> tag this can cause problems.");
	    return '';
	}
	
	if (&is_inside_of($tagstack, "head")) {
	    &end_head(@_);
	}
	
	my $extra_head = &generate_css_links();

	$currentstring = 
	    &Apache::loncommon::start_page($Apache::londefdef::title,
					   $Apache::londefdef::head
					      .$extra_head,
					   {'add_entries'    => $token->[2],
					    'no_title'       => 1,
					    'force_register' => 1});

	if ($env{'request.state'} ne 'published') {
	    $currentstring.=&Apache::lonmenu::constspaceform();
	    $currentstring.=&Apache::londefdef::edit_controls();
	}
	$currentstring.=&Apache::lonxml::message_location();
    } elsif ($target eq 'tex') {
	$currentstring = '\begin{document}';  
    } 
    return $currentstring;
}

sub edit_controls {
    my $result .= '
<form method="post">
<div class="LC_edit_problem_header">
<div class="LC_edit_problem_header_row1">'.
&Apache::lonxml::renderingoptions().'
<input type="submit" name="changeproblemmode" value="'.&mt('Change View').'" />
</div>
<div class="LC_edit_problem_header_edit_row"><input type="submit" name="editmode" accesskey="e" value="Edit" /></div></div>
</form>
<br />';
    return $result;
}

sub end_body {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = &end_p();	# Close off unclosed <p>
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= &Apache::loncommon::end_page({'discussion' => 1});
    } elsif ($target eq 'tex') {
	$currentstring .= '\strut\newline\noindent\makebox[\textwidth/$number_of_columns][b]{\hrulefill}\newline\noindent \end{document}';  
    } 
    return $currentstring;
}

# \begin{center} causes a new paragprah spacing that looks odd inside 
# of a table cell.  Same at the end of a \center but with a slightly
# larger space .. hence center_correction and center_end_correction.
#
sub center_correction { return '\vspace*{-6 mm}'; } 
sub center_end_correction { return '\vspace*{-7 mm}'; }

#-- <center> tag (end tag required)
sub start_center {
    my ($target,$token,$tagstack) = @_;
    my $currentstring = &end_p();	# Close off any prior para.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];     
    } elsif ($target eq 'tex') {
	if (&is_inside_of($tagstack, "table")) {
	    $currentstring .= &center_correction();
	}
	$currentstring .= '\begin{center}';  
    }
    return $currentstring;
}

sub end_center {
    my ($target,$token,$tagstack) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];     
    } elsif ($target eq 'tex') {
	$currentstring = '\end{center}';  
	if (&is_inside_of($tagstack, "table")) {
	    $currentstring .= &center_end_correction();
	}
    }
    return $currentstring;
}

#-- <b> tag (end tag required)
#      NOTE: In TeX mode disables internal <p>
sub start_b {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } elsif ($target eq 'tex') {
	&disable_para();
	$currentstring .= '\textbf{';  
    } 
    return $currentstring;
}

sub end_b {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];     
    } elsif ($target eq 'tex') {
	&enable_para();
	$currentstring = '}';
    } 
    return $currentstring;
}

#-- <strong> tag (end tag required)
#    NOTE: in TeX mode disables internal <p>
sub start_strong {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } elsif ($target eq 'tex') {
	&disable_para();
	$currentstring = '\textbf{';  
    } 
    return $currentstring;
}

sub end_strong {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {	
	$currentstring = $token->[2];     
    } elsif ($target eq 'tex') {
	&enable_para();
	$currentstring = '}';  
    }
    return $currentstring;
}

#-- <h1> tag (end tag required)
sub start_h1 {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = &end_p();	# Close off any prior para.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	my $pre;
	my $align=lc(&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1));
	if ($align eq 'center') {
	    $pre='\begin{center}';
	} elsif ($align eq 'left') {
	    $pre='\rlap{';
	} elsif ($align eq 'right') {
	    $pre=' \hfill \llap{';
	}
	my $TeXsize=&Apache::lonxml::get_param('TeXsize',$parstack,$safeeval,undef,0);
	if (not defined $TeXsize) {$TeXsize="large";}
	$currentstring .= '\strut\newline '.$pre.'{\\'.$TeXsize.' \textbf{'; 
    } elsif ($target eq 'meta') {
	$currentstring.='<subject>';
	&start_output($target);
    }
    return $currentstring;
}

sub end_h1 {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	my $post='\vskip 0 mm ';
	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
	if ($align eq 'center') {
	    $post='\end{center}';
	} elsif ($align eq 'left') {
	    $post='} \hfill'.'\vskip 0 mm ';
	} elsif ($align eq 'right') {
	    $post='}'.'\vskip 0 mm ';
	}
	$currentstring .= '}}'.$post;
    } elsif ($target eq 'meta') {
	&end_output($target);
	$currentstring='</subject>';
    } 
    return $currentstring;
}

#-- <h2> tag
sub start_h2 {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = &end_p();	# Close off any prior para.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	my $pre;
	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
	if ($align eq 'center') {
	    $pre='\begin{center}';
	} elsif ($align eq 'left') {
	    $pre='\rlap{';
	} elsif ($align eq 'right') {
	    $pre=' \hfill \llap{';
	}
	my $TeXsize=&Apache::lonxml::get_param('TeXsize',$parstack,$safeeval,undef,0);
	if (not defined $TeXsize) {$TeXsize="large";}
	$currentstring .= '\strut\newline '.$pre.'{\\'.$TeXsize.' \textbf{'; 
    } 
    return $currentstring;
}

sub end_h2 {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	my $post='\vskip 0 mm ';
	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
	if ($align eq 'center') {
	    $post='\end{center}';
	} elsif ($align eq 'left') {
	    $post='} \hfill'.'\vskip 0 mm ';
	} elsif ($align eq 'right') {
	    $post='}'.'\vskip 0 mm ';
	}
	$currentstring .= '}}'.$post;
    } 
    return $currentstring;
}

#-- <h3> tag
sub start_h3 {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = &end_p();	# Close off any prior para.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	my $pre;
	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
	if ($align eq 'center') {
	    $pre='\begin{center}';
	} elsif ($align eq 'left') {
	    $pre='\rlap{';
	} elsif ($align eq 'right') {
	    $pre=' \hfill \llap{';
	}
	my $TeXsize=&Apache::lonxml::get_param('TeXsize',$parstack,$safeeval,undef,0);
	if (not defined $TeXsize) {$TeXsize="large";}
	$currentstring .= '\strut\newline '.$pre.'{\\'.$TeXsize.' \textbf{'; 
    } 
    return $currentstring;
}

sub end_h3 {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	my $post='\vskip 0 mm ';
	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
	if ($align eq 'center') {
	    $post='\end{center}';
	} elsif ($align eq 'left') {
	    $post='} \hfill'.'\vskip 0 mm ';
	} elsif ($align eq 'right') {
	    $post='}'.'\vskip 0 mm ';
	}
	$currentstring .= '}}'.$post;
    } 
    return $currentstring;
}

#-- <h4> tag
sub start_h4 {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = &end_p();	# Close off any prior para.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	my $pre;
	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
	if ($align eq 'center') {
	    $pre='\begin{center}';
	} elsif ($align eq 'left') {
	    $pre='\rlap{';
	} elsif ($align eq 'right') {
	    $pre=' \hfill \llap{';
	}
	my $TeXsize=&Apache::lonxml::get_param('TeXsize',$parstack,$safeeval,undef,0);
	if (not defined $TeXsize) {$TeXsize="large";}
	$currentstring .= '\strut\newline '.$pre.'{\\'.$TeXsize.' \textbf{'; 
    } 
    return $currentstring;
}

sub end_h4 {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	my $post='\vskip 0 mm ';
	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
	if ($align eq 'center') {
	    $post='\end{center}';
	} elsif ($align eq 'left') {
	    $post='} \hfill'.'\vskip 0 mm ';
	} elsif ($align eq 'right') {
	    $post='}'.'\vskip 0 mm ';
	}
	$currentstring .= '}}'.$post;
    } 
    return $currentstring;
}

#-- <h5> tag
sub start_h5 {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = &end_p();	# Close off any prior paras.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	my $pre;
	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
	if ($align eq 'center') {
	    $pre='\begin{center}';
	} elsif ($align eq 'left') {
	    $pre='\rlap{';
	} elsif ($align eq 'right') {
	    $pre=' \hfill \llap{';
	}
	my $TeXsize=&Apache::lonxml::get_param('TeXsize',$parstack,$safeeval,undef,0);
	if (not defined $TeXsize) {$TeXsize="large";}
	$currentstring .= '\strut\newline '.$pre.'{\\'.$TeXsize.' \textbf{'; 
    } 
    return $currentstring;
}

sub end_h5 {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	my $post='\vskip 0 mm ';
	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
	if ($align eq 'center') {
	    $post='\end{center}';
	} elsif ($align eq 'left') {
	    $post='} \hfill'.'\vskip 0 mm ';
	} elsif ($align eq 'right') {
	    $post='}'.'\vskip 0 mm ';
	}
	$currentstring .= '}}'.$post;
    } 
    return $currentstring;
}

#-- <h6> tag
sub start_h6 {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = &end_p();	# Close off any prior paras.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	my $pre;
	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
	if ($align eq 'center') {
	    $pre='\begin{center}';
	} elsif ($align eq 'left') {
	    $pre='\rlap{';
	} elsif ($align eq 'right') {
	    $pre=' \hfill \llap{';
	}
	my $TeXsize=&Apache::lonxml::get_param('TeXsize',$parstack,$safeeval,undef,0);
	if (not defined $TeXsize) {$TeXsize="large";}
	$currentstring .= '\strut\newline '.$pre.'{\\'.$TeXsize.' \textbf{'; 
    } 
    return $currentstring;
}

sub end_h6 {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	my $post='\vskip 0 mm ';
	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
	if ($align eq 'center') {
	    $post='\end{center}';
	} elsif ($align eq 'left') {
	    $post='} \hfill'.'\vskip 0 mm ';
	} elsif ($align eq 'right') {
	    $post='}'.'\vskip 0 mm ';
	}
	$currentstring .= '}}'.$post;
    } 
    return $currentstring;
}

#--- <cite> tag (end tag required)
sub start_cite {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '\textit{';
    }
    return $currentstring;
}

sub end_cite {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '}';
    }
    return $currentstring;
}

#-- <i> tag (end tag required)
sub start_i {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '\textit{';
    }
    return $currentstring;
}

sub end_i {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '}';
    } 
    return $currentstring;
}

#-- <address> tag (end tag required)
sub start_address {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '\textit{';
    }
    return $currentstring;
}

sub end_address {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '}';
    }
    return $currentstring;
}

#-- <dfn> tag (end tag required)
sub start_dfn {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '\textit{';
    } 
    return $currentstring;
}

sub end_dfn {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '}';
    }
    return $currentstring;
}

#-- <tt> tag (end tag required)
sub start_tt {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '\texttt{';
    }
    return $currentstring;
}

sub end_tt {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '}';
    }
    return $currentstring;
}

#-- <kbd> tag (end tag required)
sub start_kbd {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '\texttt{';
    }
    return $currentstring;
}

sub end_kbd {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '}';
    }
    return $currentstring;
}

#-- <code> tag (end tag required)
sub start_code {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '\texttt{';
    } 
    return $currentstring;
}

sub end_code {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '}';
    } 
    return $currentstring;
}

#-- <em> tag (end tag required)
sub start_em {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '\emph{';
    }
    return $currentstring;
}

sub end_em {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '}';
    } 
    return $currentstring;
}

#-- <q> tag (end tag required)
sub start_q {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '\emph{';
    }
    return $currentstring;
}

sub end_q {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '}';
    } 
    return $currentstring;
}

#  <p> is a bit strange since it does not require a closing </p>
#  However in latex, we must often output closing stuff to end
#  environments and {}'s etc.  Therefore we do all the work
#  of figuring out the ending strings in the start tag processing,
#  and provide a mechanism to output the stop text external
#  to tag processing.
#
{

    my $closing_string = '';		# String required to close <p>

#   Some tags are <p> fragile meaning that <p> inside of them
#   does not work within TeX mode.  This is managed via the 
#   counter below:
#

    my $para_disabled = 0;

sub disable_para {
    $para_disabled++;
}
sub enable_para {
    $para_disabled--;
}


#-- <p> tag (end tag optional)
#optional attribute - align="center|left|right"
sub start_p {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= &end_p();	# close off prior para if in progress.
	$currentstring .= $token->[4];
	if (! ($currentstring =~ /\//)) {
	    $closing_string = '</p>'; # Deal correctly with <p /> e.g.
	}
    } elsif ($target eq 'tex' && !$para_disabled) {

	$currentstring .= &end_p();	# close off prior para if in progress.
	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
	if ($align eq 'center') {
	    $currentstring .='\begin{center}\par ';
	    $closing_string = '\end{center}';
	    if (&is_inside_of($tagstack, "table")) {
		$currentstring = &center_correction().$currentstring;
	    }
	} elsif ($align eq 'right') {
	    $currentstring.="\n".'{\flushright ';
#	    $currentstring.='\makebox['.$env{'form.textwidth'}.']{\hfill\llap{';
	    $closing_string= "}\n";
	} elsif ($align eq 'left') {
	    $currentstring.= "\n".'{\flushleft ';
#	    $currentstring.='\noindent\makebox['.$env{'form.textwidth'}.']{{';
	    $closing_string = "}\n";
	} else {
            $currentstring.='\par ';
	    if (&is_inside_of($tagstack, 'table')) {
		$closing_string = '\vskip 0pt'; # Seems to be consistent with <p> in tables.
	    } else {
		$closing_string = '\strut\\\\\strut ';
	    }
        }

    }
    return $currentstring;
}
#
#  End paragraph processing just requires that we output the
#  closing string that was saved and blank it.
sub end_p {
    #  Note only 'tex' mode uses disable_para and enable_para
    #  so we don't need to know the target in the check below:

    if (!$para_disabled) {
	my $current_string = $closing_string;
	$closing_string = '';	# Not in a para anymore.
	return $current_string;
    } else {
	return '';
    }

}
}
#-- <br> tag (end tag forbidden)
sub start_br {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	my @tempo=@$tagstack;
	my $signal=0;
	#  Not going to factor this to is_inside_of since that would require
        #  multiple stack traversals.
	#
	for (my $i=$#tempo;$i>=0;$i--) {
	    if (($tempo[$i] eq 'b') || ($tempo[$i] eq 'strong') ||
                ($tempo[$i] eq 'ol') || ($tempo[$i] eq 'ul'))  {
		$signal=1;
	    }
	    if (($tempo[$i] eq 'td') || ($tempo[$i] eq 'th')) {
		$signal = 1;
	    }
	}
	if ($signal != 1) {
	    $currentstring .= '\strut \\\\ \strut ';
	}
    
    }
    return $currentstring;
}

sub end_br {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    }
    return $currentstring;
}

#-- <big> tag (end tag required)
sub start_big {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '{\large ';
    } 
    return $currentstring;
}

sub end_big {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '}';
    }
    return $currentstring;
}

#-- <small> tag (end tag required)
sub start_small {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '{\footnotesize ';
    }
    return $currentstring;
}

sub end_small {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '}';
    }
    return $currentstring;
}

#-- <basefont> tag (end tag forbidden)
sub start_basefont {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } elsif ($target eq 'tex') {
	my $basesize=&Apache::lonxml::get_param('TeXsize',$parstack,$safeeval);
	if (defined $basesize) {
	    $currentstring = '{\\'.$basesize.' ';
	}
    }
    return $currentstring;
}

sub end_basefont {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } elsif ($target eq 'tex') {
	my $basesize=&Apache::lonxml::get_param('TeXsize',$parstack,$safeeval);
	if (defined $basesize) {
	    $currentstring = '}';
	}
    }
    return $currentstring;
}

#-- <font> tag (end tag required)
sub start_font {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	my $face=&Apache::lonxml::get_param('face',$parstack,$safeeval);
	if ($face!~/symbol/i) {
	    if (($env{'browser.fontenhance'} eq 'on') || 
		($env{'browser.blackwhite'} eq 'on')) { return ''; }
	}
	$currentstring = $token->[4];     
    }  elsif ($target eq 'tex') {
	my $fontsize=&Apache::lonxml::get_param('TeXsize',$parstack,$safeeval);
	if (defined $fontsize) {
	    $currentstring = '{\\'.$fontsize.' ';
	}
    }
    return $currentstring;
}

sub end_font {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    }  elsif ($target eq 'tex') {
	my $fontsize=&Apache::lonxml::get_param('TeXsize',$parstack,$safeeval);
	if (defined $fontsize) {
	    $currentstring = '}';
	}
    }
    return $currentstring;
}
 
#-- <strike> tag (end tag required)
sub start_strike {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	&Apache::lonxml::startredirection();
    } 
    return $currentstring;
}

sub end_strike {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring=&Apache::lonxml::endredirection();
	$currentstring=~s/(\S)(\s+)(\S)/$1\}$2\\underline\{$3/g; 
	$currentstring=~s/^\s*(\S)/\\underline\{$1/; 
	$currentstring=~s/(\S)\s*$/$1\}/;
    }
    return $currentstring;
}

#-- <s> tag (end tag required)
sub start_s {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	&Apache::lonxml::startredirection();
    } 
    return $currentstring;
}

sub end_s {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring=&Apache::lonxml::endredirection();
	$currentstring=~s/(\S)(\s+)(\S)/$1\}$2\\underline\{$3/g;
	$currentstring=~s/^\s*(\S)/\\underline\{$1/;
	$currentstring=~s/(\S)\s*$/$1\}/;	
    }
    return $currentstring;
}

#-- <sub> tag (end tag required)
sub start_sub {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '\raisebox{-\smallskipamount}{\scriptsize{';
    } 
    return $currentstring;
}

sub end_sub {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '}}';
    }
    return $currentstring;
}

#-- <sup> tag (end tag required)
sub start_sup {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '\raisebox{\smallskipamount}{\scriptsize{';
    } 
    return $currentstring;
}

sub end_sup {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '}}';
    }
    return $currentstring;
}

#-- <hr> tag (end tag forbidden)
sub start_hr {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = &end_p();	# End enclosing para.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {

	# <hr /> can't be inside of <sup><sub> thank you LaTeX.
	# 
	my $restart_sub = 0;
	my $restart_sup = 0;

	# Since <sub> and <sup> are simple tags it's ok to turn off/on
	# using the start_ stop_ functions.. those tags only care about
	# $target.

	if (&is_inside_of($tagstack, "sub")) {
	    $restart_sub = 1;
	    $currentstring .= &end_sub($target, $token, $tagstack, 
				       $parstack, $parser, $safeeval);
	}
	if (&is_inside_of($tagstack, "sup")) {
	    $restart_sup = 1;
	    $currentstring .= &end_sup($target, $token, $tagstack,
				       $parstack, $parser, $safeeval);
	}	

	my $LaTeXwidth = &Apache::lonxml::get_param('TeXwidth',$parstack,$safeeval,undef,0);
	if (defined $LaTeXwidth) {
	    if ($LaTeXwidth=~/^%/) {
		substr($LaTeXwidth,0,1)='';
		$LaTeXwidth=($LaTeXwidth/100).'\textwidth';
	    }
	} else {
	    $LaTeXwidth ='0.9\textwidth';
	}
	my ($pre,$post);
	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
	if (($align eq 'center') || (not defined $align)) {
	    $pre=''; $post='';
	} elsif ($align eq 'left') {
	    $pre='\rlap{'; $post='} \hfill';
	} elsif ($align eq 'right') {
	    $pre=' \hfill \llap{'; $post='}';
	}
	$currentstring .= ' \vskip 0 mm \noindent\makebox['.$LaTeXwidth.']{'.$pre.'\makebox['.
                                    $LaTeXwidth.'][b]{\hrulefill}'.$post.'}\vskip 0 mm ';
	# Turn stuff back on that we can't be inside of.

	if ($restart_sub) {
	    $currentstring .= &start_sub($target, $token, $tagstack,
					$parstack, $parser, $safeeval);
	}
	if ($restart_sup) {
	    $currentstring .= &start_sup($target, $token, $tagstack,
					 $parstack, $parser, $safeeval);
	}	
    } 
    return $currentstring;
}

sub end_hr {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    }
    return $currentstring;
}

#-- <div> tag (end tag required)
{

#  Since div can be nested, the stack below is used
#  in 'tex' mode to store the ending strings
#  for the div stack.

    my @div_end_stack;

sub start_div {
    my ($target,$token, $tagstack, $parstack, $parser, $safeeval) = @_;
    my $currentstring = &end_p();	# Close enclosing para.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } 
    if ($target eq 'tex') {
	# 4 possible alignments: left, right, center, and -missing-.
        # If inside a table row, we must let the table logic
	# do the alignment, however.
	# 

	my $endstring = '';

	my $align = lc(&Apache::lonxml::get_param('align', $parstack,
						  $safeeval, undef, 1));
	if ($align eq 'center') {
	    $currentstring .= '\begin{center}';
	    $endstring      = '\end{center}';
	    if (&is_inside_of($tagstack, "table")) {
		$currentstring = &center_correction().$currentstring;
		$endstring    .= &center_end_correction(); 
	    }
	}
	elsif ($align eq 'right') {
	    $currentstring .= '\begin{flushright}';
	    $endstring     .= '\end{flushright}';
	} elsif ($align eq 'left') {
	    $currentstring .= '\begin{flushleft}';
	    $endstring     = '\end{flushleft}';
	} else {
	
	}
	$currentstring .= "\n";   # For human readability.
	$endstring       = "\n$endstring\n"; # For human readability
	push(@div_end_stack, $endstring);
    }
    return $currentstring;
}

sub end_div {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    }
    if ($target eq 'tex') {
	my $endstring = pop @div_end_stack;
	$currentstring .= $endstring;
    }
    return $currentstring;
}
}

#-- <a> tag (end tag required)
sub start_a {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	my $href=&Apache::lonxml::get_param('href',$parstack,$safeeval,
					    undef,1);
	$currentstring=&Apache::lonenc::encrypt_ref($token,{'href'=>$href});
    }
    return $currentstring;
}

sub end_a {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    }
    if ($target eq 'tex') {
	my $href =
	    &Apache::lonxml::get_param('href',$parstack,$safeeval,undef,1);
	my $name =
	    &Apache::lonxml::get_param('name',$parstack,$safeeval,undef,1);
        my $uriprint =
            &Apache::lonxml::get_param('uriprint',$parstack,$safeeval,undef,1);
        my $anchorprint =
            &Apache::lonxml::get_param('anchorprint',$parstack,$safeeval,undef,1);
	if (($href =~ /\S/) && ($uriprint=~/^on|uriprint|yes|1$/i)) {
	    $href =~ s/([^\\])%/$1\\\%/g;
	    # Substitute special symbols... and allow line breaks at each /
	    #
	    $href = &Apache::lonxml::latex_special_symbols($href);
	    $href =~ s/\//\/\\-/g;              # Map / to /\- to allow hyphenation.
	    $currentstring .= ' ({\tt URI:'.$href.'})';
	} elsif (($name =~ /\S/) && ($anchorprint=~/^on|anchorprint|yes|1$/i)) {
	    $currentstring .= ' ({\tt Anchor:'.&Apache::lonxml::latex_special_symbols($name).'})';
	} else {
	    $currentstring.='';
	}	
    }
    return $currentstring;
}

#-- <li> tag (end tag optional)
sub start_li {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } elsif ($target eq 'tex') {
	my $type=&Apache::lonxml::get_param('type',$parstack,$safeeval,undef,0);
	my $value=&Apache::lonxml::get_param('value',$parstack,$safeeval,undef,0);
	#FIXME need to support types i and I 
	if ($type=~/disc/) {
	    $currentstring .= ' \item[$\bullet$] ';
	} elsif ($type=~/circle/) {
	    $currentstring .= ' \item[$\circ$] ';
	} elsif ($type=~/square/) {
	    $currentstring .= ' \item[$\diamond$] ';
	} elsif ($type eq '1') {
	    $currentstring .= ' \item['.($Apache::londefdef::list_index+1).'.]';
	} elsif ($type eq 'A') {
	    $currentstring .= ' \item['.('A'..'Z')[$Apache::londefdef::list_index].'.]';
	} elsif ($type eq 'a') {
	    $currentstring .= ' \item['.('a'..'z')[$Apache::londefdef::list_index].'.]';
	} elsif ($value ne '') {
	    $currentstring .= ' \item['.$value.'] ';
	} else {
	    $currentstring .= ' \item ';
	}  
	$Apache::londefdef::list_index++;
    }
    return $currentstring;
}

sub end_li {
    my ($target,$token) = @_;
    my $currentstring = &end_p();	# In case there's a <p> in the <li>
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];     
    } 
    return $currentstring;
}

#-- <u> tag (end tag required)
sub start_u {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	&Apache::lonxml::startredirection();
    } 
    return $currentstring;
}

sub end_u {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring=&Apache::lonxml::endredirection();
	$currentstring=~s/(\S)(\s+)(\S)/$1\}$2\\underline\{$3/g;
	$currentstring=~s/^\s*(\S)/\\underline\{$1/;
	$currentstring=~s/(\S)\s*$/$1\}/;		
    }
    return $currentstring;
}

#-- <ul> tag (end tag required)
sub start_ul {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = &end_p();	# Close off enclosing list.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];     
    } elsif ($target eq 'tex') {
	my $TeXtype=&Apache::lonxml::get_param('type',$parstack,$safeeval,undef,0);
	$Apache::londefdef::list_index=0;
	if ($TeXtype eq 'disc') {
	    $currentstring .= '\renewcommand{\labelitemi}{$\bullet$}'.
                              '\renewcommand{\labelitemii}{$\bullet$}'. 
                              '\renewcommand{\labelitemiii}{$\bullet$}'.
                              '\renewcommand{\labelitemiv}{$\bullet$}';
	} elsif ($TeXtype eq 'circle') {
	    $currentstring .= '\renewcommand{\labelitemi}{$\circ$}'.
                              '\renewcommand{\labelitemii}{$\circ$}'. 
                              '\renewcommand{\labelitemiii}{$\circ$}'.
                              '\renewcommand{\labelitemiv}{$\circ$}';
	} elsif ($TeXtype eq 'square') {
	    $currentstring .= '\renewcommand{\labelitemi}{$\diamond$}'.
                              '\renewcommand{\labelitemii}{$\diamond$}'. 
                              '\renewcommand{\labelitemiii}{$\diamond$}'.
                              '\renewcommand{\labelitemiv}{$\diamond$}';
	}
	$currentstring .= '\strut \begin{itemize}';  
    } 
    return $currentstring;
}

sub end_ul {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];     
    } elsif ($target eq 'tex') {
	$currentstring = '\end{itemize} \renewcommand{\labelitemi}{$\bullet$}'.
                               '\renewcommand{\labelitemii}{$\bullet$}'. 
                               '\renewcommand{\labelitemiii}{$\bullet$}'.
                               '\renewcommand{\labelitemiv}{$\bullet$}\strut ';  
    } 
    return $currentstring;
}

#-- <menu> tag (end tag required)
sub start_menu {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } elsif ($target eq 'tex') {
	$currentstring = " \\begin{itemize} ";  
    } 
    return $currentstring;
}

sub end_menu {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];     
    } elsif ($target eq 'tex') {
	$currentstring = " \\end{itemize}";  
    } 
    return $currentstring;
}

#-- <dir> tag (end tag required)
sub start_dir {
    my ($target,$token) = @_;
    my $currentstring = &end_p();	# In case there's a <p> prior to the list.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];     
    } elsif ($target eq 'tex') {
	$currentstring .= " \\begin{itemize} ";  
    } 
    return $currentstring;
}

sub end_dir {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];     
    } elsif ($target eq 'tex') {
	$currentstring = " \\end{itemize}";  
    } 
    return $currentstring;
}

#-- <ol> tag (end tag required)
sub start_ol {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = &end_p();	# In case there's a <p> prior to the list.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];     
    } elsif ($target eq 'tex') {
	$Apache::londefdef::list_index=0;
	my $type=&Apache::lonxml::get_param('type',$parstack,$safeeval,undef,0);
	if ($type eq '1') {
	    $currentstring .= '\renewcommand{\labelenumi}{\arabic{enumi}.}'.
                              '\renewcommand{\labelenumii}{\arabic{enumii}.}'. 
                              '\renewcommand{\labelenumiii}{\arabic{enumiii}.}'.
                              '\renewcommand{\labelenumiv}{\arabic{enumiv}.}';
	} elsif ($type eq 'A') {
	    $currentstring .= '\renewcommand{\labelenumi}{\Alph{enumi}.}'.
                              '\renewcommand{\labelenumii}{\Alph{enumii}.}'. 
                              '\renewcommand{\labelenumiii}{\Alph{enumiii}.}'.
                              '\renewcommand{\labelenumiv}{\Alph{enumiv}.}';
	} elsif ($type eq 'a') {
	    $currentstring .= '\renewcommand{\labelenumi}{\alph{enumi}.}'.
                              '\renewcommand{\labelenumii}{\alph{enumii}.}'.
                              '\renewcommand{\labelenumiii}{\alph{enumiii}.}'.
                              '\renewcommand{\labelenumiv}{\alph{enumiv}.}';
	} elsif ($type eq 'i') {
	    $currentstring .= '\renewcommand{\labelenumi}{\roman{enumi}.}'.
                              '\renewcommand{\labelenumii}{\roman{enumii}.}'.
                              '\renewcommand{\labelenumiii}{\roman{enumiii}.}'.
                              '\renewcommand{\labelenumiv}{\roman{enumiv}.}';
	} elsif ($type eq 'I') {
	    $currentstring .= '\renewcommand{\labelenumi}{\Roman{enumi}.}'.
                              '\renewcommand{\labelenumii}{\Roman{enumii}.}'.
                              '\renewcommand{\labelenumiii}{\Roman{enumiii}.}'.
                              '\renewcommand{\labelenumiv}{\Roman{enumiv}.}';
	}
	$currentstring .= '\strut \begin{enumerate}';  
    } 
    return $currentstring;
}

sub end_ol {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];     
    } elsif ($target eq 'tex') {
	$currentstring = '\end{enumerate}\renewcommand{\labelenumi}{\arabic{enumi}.}'.
                                        '\renewcommand{\labelenumii}{\arabic{enumii}.}'.
                                        '\renewcommand{\labelenumiii}{\arabic{enumiii}.}'.
                                        '\renewcommand{\labelenumiv}{\arabic{enumiv}.}\strut ';  
    } 
    return $currentstring;
}

#-- <dl> tag (end tag required)
sub start_dl {
    my ($target,$token) = @_;
    my $currentstring = &end_p();	# In case there's a <p> unclosed prior to the list.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];     
    } elsif ($target eq 'tex') {
	$currentstring .= '\begin{description}';
	$Apache::londefdef::DL++;
	push(@Apache::londefdef::description,[]);
	$Apache::londefdef::DD[$Apache::londefdef::DL]=0;
	$Apache::londefdef::DT[$Apache::londefdef::DL]=0;
	$Apache::londefdef::seenDT[$Apache::londefdef::DL]=0;
    } 
    return $currentstring;
}

sub end_dl {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];     
    } elsif ($target eq 'tex') {
	if ($Apache::londefdef::DT[-1]) { &end_dt(@_); }
	if ($Apache::londefdef::DD[-1]) { &end_dd(@_); }
	foreach my $element (@{$Apache::londefdef::description[-1]}) {
	    $currentstring.=' '.$element.' ';
	}
	pop(@Apache::londefdef::description);
	$currentstring.='\end{description}';  
	delete($Apache::londefdef::DD[$Apache::londefdef::DL]);
	delete($Apache::londefdef::DT[$Apache::londefdef::DL]);
	delete($Apache::londefdef::seenDT[$Apache::londefdef::DL]);
	$Apache::londefdef::DL--;
    } 
    return $currentstring;
}

#-- <dt> tag (end tag optional)
sub start_dt {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring='';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } elsif ($target eq 'tex') {
	if ($Apache::londefdef::DT[-1]) { &end_dt(@_); }
	if ($Apache::londefdef::DD[-1]) { &end_dd(@_); }
	&Apache::lonxml::startredirection();
	$Apache::londefdef::DT[-1]++;
	$Apache::londefdef::seenDT[-1]=1;
    } 
    return $currentstring;
}

sub end_dt {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } elsif ($target eq 'tex') {
	if ($Apache::londefdef::DT[-1]) {
	    my $data=&item_cleanup();
	    push(@{$Apache::londefdef::description[-1]},'\item['.$data.'] \strut \vskip 0mm');
	    $Apache::londefdef::DT[-1]--;
	}
    } 
    return $currentstring;
}

sub item_cleanup {
    my $item=&Apache::lonxml::endredirection();
    $item=~s/\\begin{center}//g;
    $item=~s/\\end{center}//g;
    return $item;
}

#-- <dd> tag (end tag optional)
sub start_dd {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } elsif ($target eq 'tex') {
	if ($Apache::londefdef::DT[-1]) { &end_dt(@_); }
	if ($Apache::londefdef::DD[-1]) { &end_dd(@_);}
	if (!$Apache::londefdef::seenDT[-1]) {
	    push(@{$Apache::londefdef::description[-1]},'\item[\strut] \strut \vskip 0mm ');
	}
	push(@{$Apache::londefdef::description[-1]},'');
	$Apache::londefdef::description[-1]->[-1].=' \strut ';
	$Apache::londefdef::DD[-1]++;
	&Apache::lonxml::startredirection();
    } 
    return $currentstring;
}

sub end_dd {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    }  elsif ($target eq 'tex') {
	$Apache::londefdef::description[-1]->[-1].=
	    &Apache::lonxml::endredirection().' \vskip 0mm ';
	$Apache::londefdef::DD[-1]--;
    }
    return $currentstring;
}

#-- <table> tag (end tag required)
#       <table> also ends any prior <p> that is not closed.
#               but, unless I allow <p>'s to nest, that's the
#               only way I could think of to allow <p> in 
#               <tr> <th> bodies
#
#list of supported attributes: border,width,TeXwidth
sub start_table {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $textwidth = '';
    my $currentstring = &end_p();
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];     
    } elsif ($target eq 'tex') {
	push(@Apache::londefdef::table, {}); 
	$Apache::londefdef::table[-1]{'row_number'} = -1;
        #maximum table's width (default coincides with text line length)
	if ($#Apache::londefdef::table==0) {
	    $textwidth=&recalc($env{'form.textwidth'}); #result is always in mm
	    $textwidth=~/(\d+\.?\d*)/;
	    $textwidth=0.85*$1; #accounts "internal" LaTeX space for table frame
	} else {
	    if ($Apache::londefdef::table[-2]{'TeXlen'}[$Apache::londefdef::table[-2]{'row_number'}][$Apache::londefdef::table[-2]{'counter_columns'}]=~/\d/) {
		#the maximum width of nested table is determined by LATeX width of parent cell
		$textwidth=$Apache::londefdef::table[-2]{'TeXlen'}[$Apache::londefdef::table[-2]{'row_number'}][$Apache::londefdef::table[-2]{'counter_columns'}]; 
	    } else {
              #try to use all space not used before (minus 5% for LaTeX table internal) - rather silly
		$textwidth=$Apache::londefdef::table[-2]{'width'};
		for (my $i=0;$i<$Apache::londefdef::table[-2]{'counter_columns'};$i++) {
		    $textwidth=$textwidth-$Apache::londefdef::table[-2]{'TeXlen'}[0][$i];
		}
	    }
	}

	# width either comes forced from the TeXwidth or the width parameters.
	# in either case it can be a percentage or absolute width.
	# in the width case we ignore absolute width 
	my $TeXwidth = &Apache::lonxml::get_param('TeXwidth',$parstack,$safeeval,undef,0);
	if (!defined($TeXwidth)) {
	    my $htmlwidth = &Apache::lonxml::get_param('width',$parstack,
						       $safeeval,undef,1);
	    if ($htmlwidth =~ /%/) {
		$TeXwidth = $htmlwidth;
	    } else { 
		$TeXwidth = $textwidth;
	    }
	}
	# if the width is specified as a % it is converted to an absolute width.
	# otherwise.. just plugged right in the hash

	if ($TeXwidth=~/%/) {
	    $TeXwidth=~/(\d+)/;
            $Apache::londefdef::table[-1]{'width'}=$1*$textwidth/100;
	} else {
	    $Apache::londefdef::table[-1]{'width'}=$TeXwidth;
	}
        #  In the end, however the table width cannot be wider than $textwidth...
	
	if ($Apache::londefdef::table[-1]{'width'} > $textwidth) {
	    $Apache::londefdef::table[-1]{'width'} = $textwidth;
	}
        #table's border
	my $border = &Apache::lonxml::get_param('border',$parstack,$safeeval); 
        my $permission=&Apache::lonxml::get_param('TeXDropEmptyColumns',$parstack,$safeeval,undef,0);
	unless (defined $border) { $border = 0; }
	if ($border) { 
	    $Apache::londefdef::table[-1]{'hinc'} = '\hline '; 
	    $Apache::londefdef::table[-1]{'vinc'} = '&'; 
	    $Apache::londefdef::table[-1]{'vvinc'} = '|';
	} else {
	    $Apache::londefdef::table[-1]{'hinc'} = ''; 
	    $Apache::londefdef::table[-1]{'vinc'} = '&'; 
	    $Apache::londefdef::table[-1]{'vvinc'} = '';
	}
	if ($#Apache::londefdef::table==0) {
	    #    Note that \newline seems to destroy the alignment envs.
	    # $Apache::londefdef::table[-1]{'output'}='\strut\newline\strut\setlength{\tabcolsep}{1 mm}';
	    $Apache::londefdef::table[-1]{'output'}='\strut'.'\\\\'."\n".'\strut\setlength{\tabcolsep}{1 mm}';
	}
	$Apache::londefdef::table[-1]{'output'}.=' \noindent \begin{tabular} ';
        $Apache::londefdef::table[-1]{'TeXlen'}=[];
        $Apache::londefdef::table[-1]{'objectlen'}=[];
        $Apache::londefdef::table[-1]{'objectsignal'}=[];
        $Apache::londefdef::table[-1]{'maxlen'}=[];
        $Apache::londefdef::table[-1]{'minlen'}=[];
        $Apache::londefdef::table[-1]{'content'}=[];
        $Apache::londefdef::table[-1]{'align'}=[];
        $currentstring.=' \keephidden{NEW TABLE ENTRY}';


    }
    return $currentstring;
}
 
sub end_table {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];     
    } elsif ($target eq 'tex') {
	my $border =  &Apache::lonxml::get_param('border',$parstack,$safeeval);
	my $inmemory = '';
	my $output = '';
	my $WARNING='';
        #width of columns from TeXwidth attributes

	# Protect against unbalanced </table> tag.

	if (scalar(@Apache::londefdef::table) > 0) {

	for (my $in=0;$in<=$Apache::londefdef::table[-1]{'row_number'};$in++) {
	    for (my $jn=0;$jn<=$Apache::londefdef::table[-1]{'counter_columns'};$jn++) {
		if ($Apache::londefdef::table[-1]{'TeXlen'}[0][$jn]<$Apache::londefdef::table[-1]{'TeXlen'}[$in][$jn]) {
		    $Apache::londefdef::table[-1]{'TeXlen'}[0][$jn]=$Apache::londefdef::table[-1]{'TeXlen'}[$in][$jn];
		}	
	    }
	}
        #free space and number of empty columns
	my ($available_space,$empty_columns)=($Apache::londefdef::table[-1]{'width'},0);
	if ($#Apache::londefdef::table ne 0) {$available_space=0.9*$available_space;} 
	for (my $jn=0;$jn<=$Apache::londefdef::table[-1]{'counter_columns'};$jn++) {
	    if ($Apache::londefdef::table[-1]{'TeXlen'}[0][$jn]==0) {
		$empty_columns++;
	    } else {
		$available_space=$available_space-$Apache::londefdef::table[-1]{'TeXlen'}[0][$jn];
	    }
	}

        #boundaries for contents columns
	my @min_len=();#columns can not be narrower 
	my @max_len=();#maximum length of column
	my $avg_max;
	my $avg_min;
	my $counter_cols = $Apache::londefdef::table[-1]{'counter_columns'};
	for (my $jn=0;$jn<=$counter_cols; $jn++) {
		my ($localmin,$localmax)=(0,0);
		for (my $in=0;$in<=$Apache::londefdef::table[-1]{'row_number'};$in++) {
		    if ($localmin<$Apache::londefdef::table[-1]{'minlen'}[$in][$jn]) {
			$localmin=$Apache::londefdef::table[-1]{'minlen'}[$in][$jn];
		    }
		    if ($localmax<$Apache::londefdef::table[-1]{'maxlen'}[$in][$jn]) {
			$localmax=$Apache::londefdef::table[-1]{'maxlen'}[$in][$jn];
		    }
		}
		push @min_len, $localmin;
		push @max_len, $localmax;
		$avg_max = $localmax + $avg_max;
		$avg_min = $localmin + $avg_min;
	}
	# Does not really matter what the average max/min are if there are no cols.
	# and this prevents div 0 in that case.

	if ($counter_cols != 0) {
	    $avg_max = $avg_max/$counter_cols;
	    $avg_min = $avg_min/$counter_cols;
	}


	#  I don't think the below is needed.. but just in case:

	if ($avg_min > $avg_max) {
	    my $temp = $avg_min;
	    $avg_min = $avg_max;
	    $avg_max = $temp;
	}


	for (my $jn=0;$jn<=$counter_cols;$jn++) {
	    my $localmin=0,;
	    for (my $in=0;$in<=$Apache::londefdef::table[-1]{'row_number'};$in++) {
		if ($localmin<$Apache::londefdef::table[-1]{'objectlen'}[$in][$jn]) {
		    $localmin=$Apache::londefdef::table[-1]{'objectlen'}[$in][$jn];
		}
	    }
	    if ($max_len[$jn]<$localmin) {
		$max_len[$jn]=$localmin;
	    	$Apache::londefdef::table[-1]{'objectsignal'}[$jn]=1;
	    }#object size is bigger
	    if ($min_len[$jn]<$localmin) {
		$min_len[$jn]=$localmin;
		$Apache::londefdef::table[-1]{'objectsignal'}[$jn]=1;
	    }#object size is bigger
	    if ($Apache::londefdef::table[-1]{'TeXlen'}[0][$jn]!=0) {
		$min_len[$jn]=0;
		$max_len[$jn]=0;
	    }
	    #  Spans seem to be really bothered by max/min = 0.  So if we have one
	    #  make it an average joe max/min.
	    
	    if ($max_len[$jn] == 0) {
		$max_len[$jn] = $avg_max;
	    }
	    if ($min_len[$jn] == 0) {
		$min_len[$jn] = $avg_min;
	    }

	}
       #final adjustment of column width
	my @fwidth=@{$Apache::londefdef::table[-1]{'TeXlen'}[0]};#final width array
	my @adjust=();
        #step 1. adjustment by maximum value
	my $space_needed=0;
	for (my $jn=0;$jn<=$#max_len;$jn++) {
	    $space_needed=$space_needed+$max_len[$jn];
	}
	if ($space_needed<=$available_space) {

	    for (my $jn=0;$jn<=$#max_len;$jn++) {
		if ($fwidth[$jn]==0) {
		    $fwidth[$jn]=$max_len[$jn];
		}
	    }
	} else {
        #step 2. adjustment by minimum value (estimation)
	    $space_needed=0;
	    for (my $jn=0;$jn<=$#min_len;$jn++) {
		$space_needed+=$min_len[$jn];
	    }
	    if ($space_needed>$available_space) {
		$WARNING=' \textbf{NOT ENOUGH SPACE FOR TABLE} ';
		for (my $jn=0;$jn<=$#max_len;$jn++) {
		    if ($fwidth[$jn]==0) {
			$fwidth[$jn]=$min_len[$jn];
		    }
		}
		#check if we have objects which can be scaled
		my $how_many_to_scale=0;
		my @to_scale=();
		for (my $jn=0;$jn<=$#max_len;$jn++) {
		    if ($Apache::londefdef::table[-1]{'objectsignal'}[$jn] eq '1') {
			$how_many_to_scale++;
			push @to_scale, $jn;
		    }
		}
		if ($how_many_to_scale>0) {
		    my $space_to_adjust=($space_needed-$available_space)/$how_many_to_scale;
		    foreach my $jn (@to_scale) {
			for (my $in=0;$in<=$Apache::londefdef::table[-1]{'row_number'};$in++) {
			    $Apache::londefdef::table[-1]{'content'}[$in][$jn]=~m/width\s*=\s*(\d+\.?\d*\s*(mm|cm|in|pc|pt)*)/;
			    if ($1 ne '') {
				my $current_length=&recalc($1);
				$current_length=~/(\d+\.?\d*)/;
				$current_length=$current_length-$space_to_adjust;
				$Apache::londefdef::table[-1]{'content'}[$in][$jn]=~s/width\s*=\s*(\d+\.?\d*\s*(mm|cm|in|pc|pt)*)/width=$current_length mm/;
			    }
			    $Apache::londefdef::table[-1]{'content'}[$in][$jn]=~m/\[(\d+\.?\d*)\s*mm\]/;
			    if ($1 ne '') {
				my $current_length=$1;
				$current_length=$current_length-$space_to_adjust;
				$Apache::londefdef::table[-1]{'content'}[$in][$jn]=~s/\[(\d+\.?\d*)\s*mm\]/\[$current_length mm\]/;
			    }				
			}
			$fwidth[$jn]=$fwidth[$jn]-$space_to_adjust;
		    }
		}
	    } else {
	      #step 3. adjustment over minimal + corrections
		my $enlarge_coef=$available_space/$space_needed;
		my $acsessive=0;
		for (my $jn=0;$jn<=$#min_len;$jn++) {
		    $adjust[$jn]=$min_len[$jn]*$enlarge_coef;
		    if ($adjust[$jn]>$max_len[$jn]) {
			$fwidth[$jn]=$max_len[$jn];
			$acsessive=$acsessive+$adjust[$jn]-$max_len[$jn];
			$adjust[$jn]=0;

		    }
		}
		if ($acsessive>0) {
		#we have an excess of space and can redistribute it
		    my $notempty_columns=0;
		    for (my $jn=0;$jn<=$#min_len;$jn++) {
			if ($adjust[$jn]!=0) {
			    $notempty_columns++;
			}
		    }
		    my $per_column=$acsessive/$notempty_columns;
		    for (my $jn=0;$jn<=$#min_len;$jn++) {
			if ($adjust[$jn]!=0) {
			    $adjust[$jn]+=$per_column;
			    $fwidth[$jn]=$adjust[$jn];
			}
		    }
		} else {
		    for (my $jn=0;$jn<=$#min_len;$jn++) {
			$fwidth[$jn]=$adjust[$jn];
		    }
		}
	    }
	}
        # use all available width or specified width as if not specified,
	# the specified width gets defaulted to the available width.

	my $current=0; 
	for (my $i=0;$i<=$#fwidth;$i++) {  
	    $current+=$fwidth[$i];
	}
	if ($current == 0) {
            $current = $Apache::londefdef::table[-1]{'width'};
        }
	my $coef=$Apache::londefdef::table[-1]{'width'}/$current;
	for (my $i=0;$i<=$#fwidth;$i++) {  
	    $fwidth[$i]*=$coef;
	}
        #removing of empty columns if allowed
        my $permission=&Apache::lonxml::get_param('TeXDropEmptyColumns',$parstack,$safeeval,undef,0);
	if ($permission eq 'yes') {
	    my @cleaned_table=();
            my @cleaned_header=();
	    my $colind=0;
	    for (my $jn=0;$jn<=$Apache::londefdef::table[-1]{'counter_columns'};$jn++) {
		if ($fwidth[$jn]!=0) {
		    #we need to copy column
		    for (my $in=0;$in<=$Apache::londefdef::table[-1]{'row_number'};$in++) {
			$cleaned_table[$in][$colind]=$Apache::londefdef::table[-1]{'content'}[$in][$jn];
			$cleaned_header[$colind]=$fwidth[$jn];
		    }
		    $colind++;
		}
	    }
	    $Apache::londefdef::table[-1]{'content'}=\@cleaned_table;
	    @fwidth=@cleaned_header;
	}


	#construct header of the table
	my $header_of_table = '{'.$Apache::londefdef::table[-1]{'vvinc'};
	for (my $in=0;$in<=$#fwidth;$in++) {
	    $header_of_table.='p{'.$fwidth[$in].' mm}'.$Apache::londefdef::table[-1]{'vvinc'};
	}
	$header_of_table .= '}';

	#fill the table
	for (my $in=0;$in<=$Apache::londefdef::table[-1]{'row_number'};$in++) {
	    my $have_rowspan = 0;
	    for (my $jn=0;$jn<=$#fwidth;$jn++) {

		#-----------------------------------------------------------
                #   I think this order of doing things will ensure that
		#   single rowspan, columspan and combined row/colspans will
                #   work correctly.  LaTeX is delicate here.
		#    RF.
		
		# Start a rowspan if necessary:
		
		my $primary_col_width = $fwidth[$jn]; # Width of primary column.
		my $rowspan = $Apache::londefdef::table[-1]{'rowspan'}[$in][$jn];
		my $colspan = $Apache::londefdef::table[-1]{'colspan'}[$in][$jn];
		#
		#  Do the appropriate magic if this has a colspan
		# 
		
		my $border_char = "";
		if ($border) {
		    $border_char = "|";
		}
		my $spanwidth = 0;
		if ($colspan > 1) {
		    for (my $spancol = $jn; $spancol < $jn + $colspan; $spancol++) {
			$spanwidth += $fwidth[$spancol];
		    }
		    $output .= '\multicolumn{'.
			$colspan
			."}";
		    if ($Apache::londefdef::table[-1]{'align'}[$in][$jn] eq 'c') {
			$output .= '{'.$border_char.'c'.$border_char.'}{';
		    } elsif ($Apache::londefdef::table[-1]{'align'}[$in][$jn] eq 'r') {
			$output .= '{'.$border_char.'r'.$border_char.'}{';
		    }
		    else {
			$output .= '{'.$border_char."p{$spanwidth mm}".$border_char.'}{';
		    }
		    
		} else {
		    $spanwidth = $primary_col_width; # If no span width will be just colwidth
		}

		# Rowspan... if colspan is 1, and there's an alignment we'll need
		# to kick in a multicolumn in order to get the alignment spec.
		# this must precede the multirow or LaTex gets quite upset.
		# Naturally if colspan > 1 we've already done that above ^
		#
		my $multirow_aligned = 0;
		if ($rowspan > 1) {
		    if ($colspan == 1) {
			if ($Apache::londefdef::table[-1]{'align'}[$in][$jn] eq 'c') {
			    $output .= '\multicolumn{1}{'.$border_char.'c'.$border_char.'}{';
			    $multirow_aligned = 1;
			} elsif ($Apache::londefdef::table[-1]{'align'}[$in][$jn] eq 'r') {
			    $output .= '\multicolumn{1}{'.$border_char.'r'.$border_char.'}{';
			    $multirow_aligned = 1;
			}
		    }
		    $have_rowspan++;
		    if ($multirow_aligned) {
			$output .= '\multirow{'.$rowspan.'}[0]{*}{';
		    } else {
			$output .= '\multirow{'.$rowspan."}[0]{$spanwidth mm}{";
		    }
		    
		    $Apache::londefdef::table[-1]{'content'}[$in][$jn] =~
			s{^\s*\\par\s*}{};
		    $Apache::londefdef::table[-1]{'content'}[$in][$jn] =~
			s{\s*\\vskip\s*0pt\s*$}{};
			  
		    #
		    # If we did not throw in a multicolumn to align, then add 
		    # an extra {
		    # so we close correctly without having to keep additional state
		    # around
		    #
		    if (!$multirow_aligned) {
			$output .= '{';
		    }
		}
		if (($rowspan eq '^') || ($rowspan eq '_')) {
		    $have_rowspan++;
		}
		    #--------------------------------------------------------------


		# For right and center alignment of single cells.
		# we are going to use a multicolumn with a span of 1 to specify alignment.
		#
		if ($colspan == 1  && $rowspan == 1) {
		    if ($Apache::londefdef::table[-1]{'align'}[$in][$jn] eq 'c') {
			$output .= '\multicolumn{1}{'.$border_char.'c'.$border_char.'}{';
		    } elsif ($Apache::londefdef::table[-1]{'align'}[$in][$jn] eq 'r') {
			$output .= '\multicolumn{1}{'.$border_char.'r'.$border_char.'}{';
		    }
		}

		$output.=$Apache::londefdef::table[-1]{'content'}[$in][$jn];

		if (($colspan == 1 && $rowspan == 1)   &&
		    (($Apache::londefdef::table[-1]{'align'}[$in][$jn] eq 'c') ||
		     ($Apache::londefdef::table[-1]{'align'}[$in][$jn] eq 'r'))) {
		    $output .= '}';
		}

		# Close off any open multirow:
		
		if ($rowspan > 1) {
		    $output .= '}}';
		}
		#  Close off the colspan...
		#
		if ($colspan > 1)  {
		    $output .= '}';
		    $jn += $colspan-1; # Adjust for number of rows really left.
		}
                if ($jn!=$#fwidth) {$output.=' '.$Apache::londefdef::table[-1]{'vinc'};}
	    }
	    #  If have_rowspan > 0, and borders are on, then 
	    #  we need to do more than put an \hline at the bottom of row.
	    #  we need to do the appropriate \cline to ensure that
	    #  the spanned rows don't have \hlines through them.

	    if (($Apache::londefdef::table[-1]{'hinc'} =~ /\\hline/) && $have_rowspan) {
		$output .= ' \\\\ ';
		for (my $jn=0; $jn<=$#fwidth;$jn++) {
		    my $rowspan = $Apache::londefdef::table[-1]{'rowspan'}[$in][$jn];
		    if ($rowspan ne "^") {
			if (($rowspan <= 1) || ($rowspan eq '_')) {
			    my $column = $jn+1;
			    $output .= '\cline{'.$column.'-'.$column.'} ';
			}
		    }
		}

	    } else {
		$output.=' \\\\ '.$Apache::londefdef::table[-1]{'hinc'}.' ';
	    }
	}
	# Note that \newline destroys alignment env's produced  by e.g. <div>
	# $Apache::londefdef::table[-1]{'output'} .= $header_of_table.$Apache::londefdef::table[-1]{'hinc'}.$output.'\end{tabular}\strut\newline\strut ';
	$Apache::londefdef::table[-1]{'output'} .= $header_of_table.$Apache::londefdef::table[-1]{'hinc'}.$output.'\end{tabular}\strut'.'\\\\'."\n".'\strut ';
	if ($#Apache::londefdef::table > 0) {	    
	    my $inmemory = $Apache::londefdef::table[-1]{'output'};
	    # Figure out max/and min width  by summing us and then
	    # apply that to the current column of the table we nest in
	    # if it's larger than the current width or the current width
	    # is undefined.
	    #
	    my $min_nested_width = 0;
	    my $max_nested_width = 0;
	    for (my $col = 0; $col <= $Apache::londefdef::table[-1]{'counter_columns'}; $col++) {
		$min_nested_width +=  $min_len[$col];
		$max_nested_width +=  $max_len[$col];
		
	    }
	    # Fudge in an extra 5 mm for borders etc:
	    
	    $min_nested_width += 5;
	    $max_nested_width += 5;

	    my $outer_column = $Apache::londefdef::table[-2]{'counter_columns'};
	    my $outer_row    = $Apache::londefdef::table[-2]{'row_number'};
	    if ($min_nested_width > $Apache::londefdef::table[-2]{'minlen'}[$outer_row][$outer_column]) {
		$Apache::londefdef::table[-2]{'minlen'}[$outer_row][$outer_column] = $min_nested_width;
	    }
	    if ($max_nested_width > $Apache::londefdef::table[-2]{'maxlen'}[$outer_row][$outer_column]) {
		$Apache::londefdef::table[-2]{'maxlen'}[$outer_row][$outer_column] = $max_nested_width;
	    }

	    pop @Apache::londefdef::table;
	    push @{$Apache::londefdef::table[-1]{'include'}}, $inmemory;
	} else {
	    $currentstring .= $Apache::londefdef::table[-1]{'output'};
	    pop @Apache::londefdef::table;
	    undef @Apache::londefdef::table;
	}
    }
    }
    return $currentstring;
}

#-- <tr> tag (end tag optional)
sub start_tr {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } elsif ($target eq 'tex') {
	$Apache::londefdef::table[-1]{'row_number'}++;
	my $alignchar=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
	if ($alignchar ne '') {
	    push @ {$Apache::londefdef::table[-1]{'rows'} },substr($alignchar,0,1);
	} else {
	    push @ {$Apache::londefdef::table[-1]{'rows'} }, 'l';
	}
	push ( @{ $Apache::londefdef::table[-1]{'rowdata'} }, $Apache::londefdef::table[-1]{'hinc'});
	#
	#  Need to save the number of table columns to preserve the max # columns.
	#
	$Apache::londefdef::table[-1]{'prior_columns'}   = $Apache::londefdef::table[-1]{'counter_columns'};
	$Apache::londefdef::table[-1]{'counter_columns'} = -1;
	push @ {$Apache::londefdef::table[-1]{'TeXlen'}}, [];
	push @ {$Apache::londefdef::table[-1]{'objectlen'}}, [];
	push @ {$Apache::londefdef::table[-1]{'minlen'}}, [];
	push @ {$Apache::londefdef::table[-1]{'maxlen'}}, [];
	push @ {$Apache::londefdef::table[-1]{'content'}}, [];
    } 
    return $currentstring;
}
        
sub end_tr {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = &end_p();	# Close any pending <p> in the row.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];     
    } elsif ($target eq 'tex') {
	if ($Apache::londefdef::TD_redirection) {
	    &end_td_tex($parstack,$parser,$safeeval);    
	}
	# Counter columns must be the maximum number of columns seen
	# in the table so far so:
	if ($Apache::londefdef::table[-1]{'prior_columns'} > $Apache::londefdef::table[-1]{'counter_columns'}) {
	    $Apache::londefdef::table[-1]{'counter_columns'} = $Apache::londefdef::table[-1]{'prior_columns'};
	}


	
    }
    return $currentstring;
}

#-- <td> tag (end tag optional)
sub start_td {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } elsif ($target eq 'tex') {
	$Apache::londefdef::TD_redirection = 1;
	&tag_check('tr','td',$tagstack,$parstack,$parser,$safeeval);
    } 
    return $currentstring;
}   
    
sub tag_check {
    my ($good_tag,$bad_tag,$tagstack,$parstack,$parser,$safeeval) = @_;
    my @ar=@$parstack; 
    for (my $i=$#ar-1;$i>=0;$i--) {
	if (lc($$tagstack[$i]) eq $good_tag) {
	    &start_td_tex($parstack,$parser,$safeeval);
	    last;
	} elsif (lc($$tagstack[$i]) eq $bad_tag) {
	    splice @ar, $i+1;
	    &end_td_tex(\@ar,$parser,$safeeval);
	    &start_td_tex($parstack,$parser,$safeeval);
	    last;
	}
    }
    return '';
}
 
sub start_td_tex {
    my ($parstack,$parser,$safeeval) = @_;
    my $alignchar = substr(&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1),0,1);
    if ($alignchar eq '') {
	$alignchar = $Apache::londefdef::table[-1]{'rows'}[-1];
    }
    push @{ $Apache::londefdef::table[-1]{'align'}[$Apache::londefdef::table[-1]{'row_number'}] }, $alignchar;
    $Apache::londefdef::table[-1]{'counter_columns'}++;
    my $TeXwidth=&Apache::lonxml::get_param('TeXwidth',$parstack,$safeeval,undef,0);
    if (defined $TeXwidth) {		
	my $current_length=&recalc($TeXwidth);
	$current_length=~/(\d+\.?\d*)/;
	push @ {$Apache::londefdef::table[-1]{'TeXlen'}[$Apache::londefdef::table[-1]{'row_number'}] },$1;
    }
    &Apache::lonxml::startredirection();
    return '';
}

sub end_td_tex {
    my ($parstack,$parser,$safeeval) = @_;
    my $current_row    = $Apache::londefdef::table[-1]{'row_number'};
    my $current_column = $Apache::londefdef::table[-1]{'counter_columns'}; 
    my $data = &Apache::lonxml::endredirection();

    #  The rowspan array of the table indicates which cells are part of a span.
    #  n indicates the start of a span set of n rows.
    #  ^ indicates a cell that continues a span set.
    #  _ indicates the cell is at the bottom of a span set.
    #  If this and subsequent cells are part of a rowspan, we must
    #  push along the row until we find one that is not.

    while ((defined $Apache::londefdef::table[-1]{'rowspan'}[$current_row] [$current_column]) 
	   && ($Apache::londefdef::table[-1]{'rowspan'}[$current_row][$current_column] =~ /[\^\_]/)) {
	# Part of a span.
	push @ {$Apache::londefdef::table[-1]{'content'}[-1]}, '';
	$current_column++;
    }
    $Apache::londefdef::table[-1]{'counter_columns'} = $current_column;
   

    # Get the column and row spans.
    # Colspan can be done via \multicolumn if I can figure out the data structs.

    my $colspan = &Apache::lonxml::get_param('colspan', $parstack, $safeeval, undef, 0);
    if (!$colspan) {
	$colspan = 1;
    }

    my $rowspan = &Apache::lonxml::get_param('rowspan', $parstack, $safeeval, undef, 0);
    if (!$rowspan) {
	$rowspan = 1;
    }



    for (my $c = 0; $c < $colspan; $c++) {
	$Apache::londefdef::table[-1]{'rowspan'}[$current_row][$current_column+$c] = $rowspan;
	for (my $i = 1; $i < $rowspan; $i++) {
	    $Apache::londefdef::table[-1]{'rowspan'}[$current_row+$i][$current_column+$c] = '^';
	    if ($i == ($rowspan-1)) {
		$Apache::londefdef::table[-1]{'rowspan'}[$current_row+$i][$current_column+$c] = '_';
	    }
	}
    }

    my $TeXwidth=&Apache::lonxml::get_param('TeXwidth',$parstack,$safeeval,undef,0);
    if (defined $TeXwidth) {		
	for (my $c = 0; $c < $colspan; $c++) {
	    push @ {$Apache::londefdef::table[-1]{'objectlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
	    push @ {$Apache::londefdef::table[-1]{'minlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
	    push @ {$Apache::londefdef::table[-1]{'maxlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
	}
    } else {
	if (($data=~m/width\s*=\s*(\d+\.?\d*\s*(mm|cm|in|pc|pt)*)/) or ($data=~m/\[(\d+\.?\d*)\s*mm\]/)) {
	    my $garbage_data=$data;
	    my $fwidth=0;
            while ($garbage_data=~m/width\s*=\s*(\d+\.?\d*\s*(mm|cm|in|pc|pt)*)/) {
		my $current_length=&recalc($1);
		$current_length=~/(\d+\.?\d*)/;
		if ($fwidth<$1) {$fwidth=$1;}
		$garbage_data=~s/width\s*=\s*(\d+\.?\d*\s*(mm|cm|in|pc|pt)*)//;
	    }
            while ($garbage_data=~m/\[(\d+\.?\d*)\s*mm\]/) {
		my $current_length=$1;
		if ($fwidth<$current_length) {$fwidth=$current_length;}
		$garbage_data=~s/\[(\d+\.?\d*)\s*mm\]//;
	    }
	    for (my $c = 0; $c < $colspan; $c++) {
		push @ {$Apache::londefdef::table[-1]{'TeXlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
		push @ {$Apache::londefdef::table[-1]{'objectlen'}[$Apache::londefdef::table[-1]{'row_number'}] },$fwidth;
		push @ {$Apache::londefdef::table[-1]{'minlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
		push @ {$Apache::londefdef::table[-1]{'maxlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
	    }
	} elsif ($data=~/\\parbox\{\s*\d+\.?\d*\s*(mm|cm|in|pc|pt)*\s*\}/ or $data=~/\\epsfxsize\s*=\s*\d+\.?\d*\s*(mm|cm|in|pc|pt)*/) {
	    my $garbage_data=$data;
	    my $fwidth=0;
            while ($garbage_data=~/\\parbox\{\s*(\d+\.?\d*\s*(mm|cm|in|pc|pt)*)\s*\}/) {
		my $current_length=&recalc($1);
		$current_length=~/(\d+\.?\d*)/;
		if ($fwidth<$1) {$fwidth=$1;}
		$garbage_data=~s/\\parbox\{\s*(\d+\.?\d*\s*(mm|cm|in|pc|pt)*)//;
	    }
            while ($garbage_data=~/\\epsfxsize\s*=\s*(\d+\.?\d*\s*(mm|cm|in|pc|pt)*)/) {
		my $current_length=&recalc($1);
		$current_length=~/(\d+\.?\d*)/;
		if ($fwidth<$1) {$fwidth=$1;}
		$garbage_data=~s/\\epsfxsize\s*=\s*(\d+\.?\d*\s*(mm|cm|in|pc|pt)*)//;
	    }
	    for (my $c = 0; $c < $colspan; $c++) {
		push @ {$Apache::londefdef::table[-1]{'TeXlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
		push @ {$Apache::londefdef::table[-1]{'objectlen'}[$Apache::londefdef::table[-1]{'row_number'}] },$fwidth;
		push @ {$Apache::londefdef::table[-1]{'minlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
		push @ {$Apache::londefdef::table[-1]{'maxlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
	    }
	    $data=~s/\\\\\s*$//; 
	} else {  
	    $data=~s/^\s+(\S.*)/$1/; 
	    $data=~s/(.*\S)\s+$/$1/;
	    $data=~s/(\s)+/$1/;
	    my ($current_length,$min_length)=(0,0);
	    if ($data=~/\\vskip/) {
                my $newdata=$data;
		$newdata=~s/\\vskip \d*\.?\d*\s*mm/THISISJUSTTEMPORARYSEPARATOR/g;
		my @newdata=split(/THISISJUSTTEMPORARYSEPARATOR/,$newdata);
		foreach my $elementdata (@newdata) {
		    my $lengthnewdata=2.5*&LATEX_length($elementdata);
		    if ($lengthnewdata>$current_length) {$current_length=$lengthnewdata;}
                    my @words=split(/ /,$elementdata);
		    foreach my $word (@words) {
			my $lengthword=2.5*&LATEX_length($word);
			if ($min_length<$lengthword) {$min_length=$lengthword;}
		    }
		}
	    } else {
		$current_length=2.5*&LATEX_length($data);
                    my @words=split(/ /,$data);
		    foreach my $word (@words) {
			my $lengthword=2*&LATEX_length($word);
			if ($min_length<$lengthword) {$min_length=$lengthword;}
		    }
	    }
	    for (my $c = 0; $c < $colspan; $c++) {
		push @ {$Apache::londefdef::table[-1]{'TeXlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
		push @ {$Apache::londefdef::table[-1]{'objectlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
		push @ {$Apache::londefdef::table[-1]{'maxlen'}[$Apache::londefdef::table[-1]{'row_number'}] },$current_length;
		push @ {$Apache::londefdef::table[-1]{'minlen'}[$Apache::londefdef::table[-1]{'row_number'}] },$min_length;
	    }
	}        
    }
    # Substitute all of the tables nested in this cell in their appropriate places.


    my $nested_count = $#{$Apache::londefdef::table[-1]{'include'}}; # This one is constant...
    for (my $in=0; $in<=$nested_count; $in++) {    
	my $nested = shift @{$Apache::londefdef::table[-1]{'include'}};
	$nested =~ s/\\end\{tabular\}\\strut\\\\/\\end\{tabular\}/;
	# $data=~s/\\keephidden\{NEW TABLE ENTRY\}/$Apache::londefdef::table[-1]{'include'}[$in]/;
	$data =~ s/\\keephidden\{NEW TABLE ENTRY\}/$nested/;

    }
    # Should be be killing off the 'include' elements as they're used up?

    push @ {$Apache::londefdef::table[-1]{'content'}[-1] },$data;




    #  the colspan array will indicate how many columns will be spanned by this
    #  cell..this requires that counter_columns also be adjusted accordingly
    #  so that the next bunch of text goes in the right cell.  Note that since
    #  counter_columns is incremented in the start_td_tex, we adjust by colspan-1.
    #

    $Apache::londefdef::table[-1]{'counter_columns'} += $colspan -1;
    for (my $i = 0; $i < ($colspan -1); $i++) {
	push @ {$Apache::londefdef::table[-1]{'content'}[-1] },'';
    }
    for (my $r = 0; $r < $rowspan; $r++) {
	$Apache::londefdef::table[-1]{'colspan'}[$current_row+$r][$current_column] = $colspan;
	# Put empty text in spanned cols.
	
    }



    return '';
}

sub end_td {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];     
    } elsif ($target eq 'tex') {
        $Apache::londefdef::TD_redirection =0;
	&end_td_tex($parstack,$parser,$safeeval);
    }
    return $currentstring;
}

#-- <th> tag (end tag optional)
sub start_th {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } elsif ($target eq 'tex') {
	$Apache::londefdef::TD_redirection = 1;
	&tagg_check('tr','th',$tagstack,$parstack,$parser,$safeeval);
    } 
    return $currentstring;
}   
    
sub tagg_check {
    my ($good_tag,$bad_tag,$tagstack,$parstack,$parser,$safeeval) = @_;
    my @ar=@$parstack; 
    for (my $i=$#ar-1;$i>=0;$i--) {
	if (lc($$tagstack[$i]) eq $good_tag) {
	    &start_th_tex($parstack,$parser,$safeeval);
	    last;
	} elsif (lc($$tagstack[$i]) eq $bad_tag) {
	    splice @ar, $i+1;
	    &end_th_tex(\@ar,$parser,$safeeval);
	    &start_th_tex($parstack,$parser,$safeeval);
	    last;
	}
    }
    return '';
}
 
sub start_th_tex {
    my ($parstack,$parser,$safeeval) = @_;
    my $alignchar = substr(&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1),0,1);
    if ($alignchar eq '') {
	$alignchar = $Apache::londefdef::table[-1]{'rows'}[-1];
    }
    push @{ $Apache::londefdef::table[-1]{'align'}[$Apache::londefdef::table[-1]{'row_number'}] }, $alignchar;
    $Apache::londefdef::table[-1]{'counter_columns'}++;
    my $TeXwidth=&Apache::lonxml::get_param('TeXwidth',$parstack,$safeeval,undef,0);
    if (defined $TeXwidth) {		
	my $current_length=&recalc($TeXwidth);
	$current_length=~/(\d+\.?\d*)/;
	push @ {$Apache::londefdef::table[-1]{'TeXlen'}[$Apache::londefdef::table[-1]{'row_number'}] },$1;
    }
    &Apache::lonxml::startredirection();
    return '';
}

sub end_th_tex {
    my ($parstack,$parser,$safeeval) = @_;
    my $current_row = $Apache::londefdef::table[-1]{'row_number'};
    my $data=&Apache::lonxml::endredirection();
    my $TeXwidth=&Apache::lonxml::get_param('TeXwidth',$parstack,$safeeval,undef,0);
    if (defined $TeXwidth) {		
	push @ {$Apache::londefdef::table[-1]{'objectlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
	push @ {$Apache::londefdef::table[-1]{'minlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
	push @ {$Apache::londefdef::table[-1]{'maxlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
    } else {
	if (($data=~m/width\s*=\s*(\d+\.?\d*\s*(mm|cm|in|pc|pt)*)/) or ($data=~m/\[(\d+\.?\d*)\s*mm\]/)) {
	    my $garbage_data=$data;
	    my $fwidth=0;
            while ($garbage_data=~m/width\s*=\s*(\d+\.?\d*\s*(mm|cm|in|pc|pt)*)/) {
		my $current_length=&recalc($1);
		$current_length=~/(\d+\.?\d*)/;
		if ($fwidth<$1) {$fwidth=$1;}
		$garbage_data=~s/width\s*=\s*(\d+\.?\d*\s*(mm|cm|in|pc|pt)*)//;
	    }
            while ($garbage_data=~m/\[(\d+\.?\d*)\s*mm\]/) {
		my $current_length=$1;
		if ($fwidth<$current_length) {$fwidth=$current_length;}
		$garbage_data=~s/\[(\d+\.?\d*)\s*mm\]//;
	    }
	    push @ {$Apache::londefdef::table[-1]{'TeXlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
	    push @ {$Apache::londefdef::table[-1]{'objectlen'}[$Apache::londefdef::table[-1]{'row_number'}] },$fwidth;
	    push @ {$Apache::londefdef::table[-1]{'minlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
	    push @ {$Apache::londefdef::table[-1]{'maxlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
	} else {  
	    $data=~s/^\s+(\S.*)/$1/; 
	    $data=~s/(.*\S)\s+$/$1/;
	    $data=~s/(\s)+/$1/;
	    my ($current_length,$min_length)=(0,0);
	    if ($data=~/\\vskip/) {
                my $newdata=$data;
		$newdata=~s/\\vskip \d*\.?\d*\s*mm/THISISJUSTTEMPORARYSEPARATOR/g;
		my @newdata=split(/THISISJUSTTEMPORARYSEPARATOR/,$newdata);
		foreach my $elementdata (@newdata) {
		    my $lengthnewdata=2.5*&LATEX_length($elementdata);
		    if ($lengthnewdata>$current_length) {$current_length=$lengthnewdata;}
                    my @words=split(/ /,$elementdata);
		    foreach my $word (@words) {
			my $lengthword=2.5*&LATEX_length($word);
			if ($min_length<$lengthword) {$min_length=$lengthword;}
		    }
		}
	    } else {
		$current_length=2.5*&LATEX_length($data);
                    my @words=split(/ /,$data);
		    foreach my $word (@words) {
			my $lengthword=2*&LATEX_length($word);
			if ($min_length<$lengthword) {$min_length=$lengthword;}
		    }
	    }
	    push @ {$Apache::londefdef::table[-1]{'TeXlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
	    push @ {$Apache::londefdef::table[-1]{'objectlen'}[$Apache::londefdef::table[-1]{'row_number'}] },'0';
	    push @ {$Apache::londefdef::table[-1]{'maxlen'}[$Apache::londefdef::table[-1]{'row_number'}] },$current_length;
	    push @ {$Apache::londefdef::table[-1]{'minlen'}[$Apache::londefdef::table[-1]{'row_number'}] },$min_length;
	}        
    }
	for (my $in=0; $in<=$#{$Apache::londefdef::table[-1]{'include'}};$in++) {         
	    $data=~s/\\keephidden\{NEW TABLE ENTRY\}/$Apache::londefdef::table[-1]{'include'}[$in]/;
	}
    #make data bold
    $data='\textbf{'.$data.'}';
    push @ {$Apache::londefdef::table[-1]{'content'}[-1] },$data;
    return'';
}

sub end_th {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = &end_p();	# Close any open <p> in the row.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];     
    } elsif ($target eq 'tex') {
        $Apache::londefdef::TD_redirection =0;
	&end_th_tex($parstack,$parser,$safeeval);
    }
    return $currentstring;
}
     
#-- <img> tag (end tag forbidden)
#
#  Render the <IMG> tag.
#     <IMG> has the following attributes (in addition to the 
#     standard HTML ones:
#      TeXwrap   - Governs how the tex target will try to wrap text around
#                  horizontally aligned images.
#      TeXwidth  - The width of the image when rendered for print (mm).
#      TeXheight - The height of the image when rendered for print (mm)
#         (Note there seems to also be support for this as a % of page size)
#      
sub start_img {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
    my $src = &Apache::lonxml::get_param('src',$parstack,$safeeval,
					 undef,1);
    if (! $src && 
	($target eq 'web' || $target eq 'webgrade' || $target eq 'tex')
	) { 
	my $inside = &Apache::lonxml::get_all_text("/img",$parser,$style);
	return '';
    }
    &Apache::lonxml::extlink($src);
    my $currentstring = '';
    my $scaling = .3;

   # Render unto browsers that which are the browser's...

    if ($target eq 'web' || $target eq 'webgrade') {
	if ($env{'browser.imagesuppress'} ne 'on') {
	    my $enc = ('yes' eq 
		       lc(&Apache::lonxml::get_param('encrypturl',$parstack,
						     $safeeval)));
	    $currentstring.=&Apache::lonenc::encrypt_ref($token,{'src'=>$src},
							 $enc);
	} else {
	    my $alttag = &Apache::lonxml::get_param('alt',$parstack,$safeeval,
						    undef,1);
	    if (!$alttag) {
		$alttag = &Apache::lonmeta::alttag($Apache::lonxml::pwd[-1],
						   $src);
	    }
	    $currentstring.='[IMAGE: '.$alttag.']';
	}

	# and render unto TeX that which is LaTeX

    } elsif ($target eq 'tex') {
	#
	#  The alignment will require some superstructure to be put around
	#  the \includegraphics stuff.  At present we can only partially
	#  simulate the alignments offered by html.
	#
	#
	my $align = lc(&Apache::lonxml::get_param('align', 
						  $parstack,
						  $safeeval,
						  undef,1));
	if(!$align) {
		$align = "bottom";	# This is html's default so it's ours too.
	}
	#
	&Apache::lonxml::debug("Alignemnt = $align");
	#  LaTeX's image/text wrapping is really bad since it wants to
	#  make figures float.  
        #   The user has the optional parameter (applicable only to l/r
	# alignment to use the picins/parpic directive to get wrapped text
	# this is also imperfect.. that's why we give them a choice...
	# so they can't yell at us for our choice.
	#
	my $latex_rendering = &Apache::lonxml::get_param('TeXwrap',
							    $parstack,
							    $safeeval,
							    undef,0);
	# &Apache::lonxml::debug("LaTeX rendering = $latex_rendering");
	if(!$latex_rendering) {
		$latex_rendering = "texwrap";
	}
	# using texwrap inside a table does not work. So, if after all of this,
	# texwrap is on, we turn it off if we detect we're in a table:
	#
	if (($latex_rendering eq 'texwrap') && &is_inside_of($tagstack, "table")) {
	    $latex_rendering = 'parpic';
	}

	# &Apache::lonxml::debug("LaTeX rendering = $latex_rendering image file: $src");

	#if original bmp/gif/jpg/png file exist do following:
	my $origsrc=$src;
	my ($path,$file) = &get_eps_image($src);
	# &Apache::lonnet::logthis("Image source: $src result: $path $file");
	$src=&Apache::lonnet::filelocation($Apache::lonxml::pwd[-1],$src);
	&Apache::lonxml::debug("path = $path file = $file src = $src");
	if (-e $src) {
	    &Apache::lonxml::debug("$src exists");
	    my ($height_param,$width_param)=
		&image_size($origsrc,0.3,$parstack,$safeeval);
	    my $size;
	    if ($width_param)  { $size.='width='.$width_param.' mm,'; }
	    if ($height_param) { $size.='height='.$height_param.' mm]'; }
	    # Default size if not able to extract that (e.g. eps image).
	    
	    # &Apache::lonnet::logthis("Size = $size");
	    
	    $size='['.$size;
	    $size=~s/,$/]/; 
	    $currentstring .= '\graphicspath{{'.$path.'}}'
		.'\includegraphics'.$size.'{'.$file.'} ';
	    my $closure;
	    ($currentstring, $closure) = &align_latex_image($align, 
							    $latex_rendering, 
							    $currentstring, 
							    $width_param, 
							    $height_param);
	    $currentstring .= $closure;
						
	} else {
	    &Apache::lonxml::debug("$src does not exist");
	    #original image file doesn't exist so check the alt attribute
	    my $alt = 
		&Apache::lonxml::get_param('alt',$parstack,$safeeval,undef,1);
	    unless ($alt) {
		$alt=&Apache::lonmeta::alttag($Apache::lonxml::pwd[-1],$src);
	    }

	    if ($alt) { $currentstring .= ' '.$alt.' '; }
	}

	# And here's where the semi-quote breaks down: allow the user
        # to edit the beast as well by rendering the problem for edit:
    } elsif ($target eq 'edit') {
        my $only = join(',',&Apache::loncommon::filecategorytypes('Pictures'));
	$currentstring .=&Apache::edit::tag_start($target,$token);
	$currentstring .=&Apache::edit::text_arg('Image Url:','src',$token,70).
	    &Apache::edit::browse('src',undef,'alt',$only).' '.
	    &Apache::edit::search('src',undef,'alt').'<br />';
	$currentstring .=&Apache::edit::text_arg('Description:','alt',$token,70).'<br />';
	$currentstring .=&Apache::edit::text_arg('width (pixel):','width',$token,5);
	$currentstring .=&Apache::edit::text_arg('height (pixel):','height',$token,5).'<br />';
	$currentstring .=&Apache::edit::text_arg('TeXwidth (mm):','TeXwidth',$token,5);
	$currentstring .=&Apache::edit::text_arg('TeXheight (mm):','TeXheight',$token,5);
	$currentstring .=&Apache::edit::select_arg('Alignment:','align',
						   ['','bottom','middle','top','left','right'],$token,5);
	$currentstring .=&Apache::edit::select_arg('TeXwrap:', 'TeXwrap',
						   ['', 'none','parbox', 'parpic', 'wrapfigure'], $token, 2);
	$currentstring .=&Apache::edit::select_arg('Encrypt URL:','encrypturl',
						   ['no','yes'], $token, 2);
	$currentstring .=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
	my $src=    &Apache::lonxml::get_param('src',$parstack,$safeeval);
	my $alt=    &Apache::lonxml::get_param('alt',$parstack,$safeeval);
	my $width=  &Apache::lonxml::get_param('width',$parstack,$safeeval);
	my $height= &Apache::lonxml::get_param('height',$parstack,$safeeval);

        if ($token->[2]{'src'}=~/\$/) {
           $currentstring.='Variable image source';
        } else {
	   $currentstring .= '<img src="'.$src.'" alt="'.$alt.'" ';
	   if ($width) { $currentstring.=' width="'.$width.'" '; }
	   if ($height) { $currentstring.=' height="'.$height.'" '; }
	   $currentstring .= ' />';
        }
    } elsif ($target eq 'modified') {
	my ($osrc,$owidth,$oheight)=
	    ($token->[2]{'src'},$token->[2]{'width'},$token->[2]{'height'});
	my $ctag=&Apache::edit::get_new_args($token,$parstack,
					     $safeeval,'src','alt','align',
					     'TeXwidth','TeXheight', 'TeXwrap',
					     'width','height','encrypturl');
	my ($nsrc,$nwidth,$nheight)=
	    ($token->[2]{'src'},$token->[2]{'width'},$token->[2]{'height'});
	my $loc=&Apache::lonnet::filelocation($Apache::lonxml::pwd[-1],$nsrc);
	&image_replication($loc);
	my ($iwidth,$iheight);
	if (-e $loc) {
	    my $image = Image::Magick->new;
	    $image->Read($loc);
	    ($iwidth, $iheight) = ($image->Get('width'),
				   $image->Get('height'));
	}
	if ($osrc ne $nsrc || (!$nwidth && !$nheight)) {
	    # changed image or no size specified,
            # if they didn't explicitly change the 
            # width or height use the ones from the image
	    if ($iwidth && $iheight) {
		if ($owidth == $nwidth || (!$nwidth && !$nheight)) {
		    $token->[2]{'width'} = $iwidth;$ctag=1;
		}
		if ($oheight == $nheight || (!$nwidth && !$nheight)) {
		    $token->[2]{'height'}=$iheight;$ctag=1;
		}
	    }
	}
	my ($cwidth,$cheight)=($token->[2]{'width'},$token->[2]{'height'});
	# if we don't have a width or height
	if ($iwidth && $cwidth && !$cheight) {
	    $token->[2]{'height'}=int(($cwidth/$iwidth)*$iheight);$ctag=1;
	}
	if ($iheight && $cheight && !$cwidth) {
	    $token->[2]{'width'}=int(($cheight/$iheight)*$iwidth);$ctag=1;
	}
	if ($ctag) {$currentstring=&Apache::edit::rebuild_tag($token);}
    }

    return $currentstring;
}

sub end_img {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring = '';
    }
    return $currentstring;
}

#-- <applet> tag (end tag required)
sub start_applet {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    
    my $code=&Apache::lonxml::get_param('code',$parstack,$safeeval,undef,1);
    &Apache::lonxml::extlink($code);
    my $archive=&Apache::lonxml::get_param('archive',$parstack,$safeeval,
					   undef,1);
    &Apache::lonxml::extlink($archive);
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	if ($env{'browser.appletsuppress'} ne 'on') {
	    $currentstring = &Apache::lonenc::encrypt_ref($token,
							  {'code'=>$code,
							   'archive'=>$archive}
							  );
	} else {
	    my $alttag= &Apache::lonxml::get_param('alt',$parstack,
						   $safeeval,undef,1);
	    unless ($alttag) {
		$alttag=&Apache::lonmeta::alttag($Apache::lonxml::pwd[-1],
						 $code);
	    }
	    $currentstring='[APPLET: '.$alttag.']';
	}
    } elsif ($target eq 'tex') {
	# Turn off some stuff we can't be inside thank you LaTeX
	

	my $restart_sub = 0;
	my $restart_sup = 0;

	# Since <sub> and <sup> are simple tags it's ok to turn off/on
	# using the start_ stop_ functions.. those tags only care about
	# $target.

	if (&is_inside_of($tagstack, "sub")) {
	    $restart_sub = 1;
	    $currentstring .= &end_sub($target, $token, $tagstack, 
				       $parstack, $parser, $safeeval);
	}
	if (&is_inside_of($tagstack, "sup")) {
	    $restart_sup = 1;
	    $currentstring .= &end_sup($target, $token, $tagstack,
				       $parstack, $parser, $safeeval);
	}

	# Now process the applet; just replace it with its alt attribute.

	my $alttag= &Apache::lonxml::get_param('alt',$parstack,
					       $safeeval,undef,1);
	unless ($alttag) {
	    my $code=&Apache::lonxml::get_param('code',$parstack,$safeeval,
						undef,1);
	    $alttag=&Apache::lonmeta::alttag($Apache::lonxml::pwd[-1],
					     $code);
	}
	$currentstring.='\begin{center} \fbox{Java Applet: '.$alttag.
	    '.}\end{center}';

	# Turn stuff back on that we can't be inside of.

	if ($restart_sub) {
	    $currentstring .= &start_sub($target, $token, $tagstack,
					$parstack, $parser, $safeeval);
	}
	if ($restart_sup) {
	    $currentstring .= &start_sup($target, $token, $tagstack,
					 $parstack, $parser, $safeeval);
	}
    } 
    return $currentstring;
}

sub end_applet {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];
    } elsif ($target eq 'tex') {
    } 
    return $currentstring;
}

#-- <embed> tag (end tag optional/required)
sub start_embed {    
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $src=&Apache::lonxml::get_param('src',$parstack,$safeeval,undef,1);
    &Apache::lonxml::extlink($src);
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	if ($env{'browser.embedsuppress'} ne 'on') {
	    $currentstring=&Apache::lonenc::encrypt_ref($token,{'src'=>$src});
	} else {
	    my $alttag=&Apache::lonxml::get_param
		('alt',$parstack,$safeeval,undef,1);
	    unless ($alttag) {
		$alttag=&Apache::lonmeta::alttag($Apache::lonxml::pwd[-1],$src);
	    }
	    $currentstring='[EMBED: '.$alttag.']';
	}
    } elsif ($target eq 'tex') {
    } 
    return $currentstring;
}

sub end_embed {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];     
    } elsif ($target eq 'tex') {  
    } 
    return $currentstring;
}

#-- <param> tag (end tag forbidden)
sub start_param {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    if (&Apache::lonxml::get_param('name',$parstack,
				   $safeeval,undef,1)=~/^cabbase$/i) {
	my $value=&Apache::lonxml::get_param('value',$parstack,
					     $safeeval,undef,1);
	&Apache::lonxml::extlink($value);
    } 
  
    my $src = &Apache::lonxml::get_param('src',$parstack,$safeeval,undef,1);
    &Apache::lonxml::extlink($src);
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	my %toconvert;
	my $src=&Apache::lonxml::get_param('src',$parstack,$safeeval,undef,1);
	if ($src) { $toconvert{'src'}= $src; }
	my $name=&Apache::lonxml::get_param('name',$parstack,$safeeval,
					    undef,1);
	if ($name=~/^cabbase$/i) {
	    $toconvert{'value'}=&Apache::lonxml::get_param('value',$parstack,
							   $safeeval,undef,1);
	}
	$currentstring = &Apache::lonenc::encrypt_ref($token,\%toconvert);
    } elsif ($target eq 'tex') {
    } 
    return $currentstring;
}

sub end_param {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];     
    } elsif ($target eq 'tex') {
    } 
    return $currentstring;
}

#-- <allow> tag
sub start_allow {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $src = &Apache::lonxml::get_param('src',$parstack,$safeeval,undef,1);
    &Apache::lonxml::extlink($src);

    if ($target eq 'tex') { &image_replication($src); }
    my $result;
    if ($target eq 'edit') {
	$result .=&Apache::edit::tag_start($target,$token);
	$result .=&Apache::edit::text_arg('File Spec:','src',$token,70);
	$result .=&Apache::edit::end_row();#.&Apache::edit::start_spanning_row();
    } elsif ($target eq 'modified') {
	my $constructtag=&Apache::edit::get_new_args($token,$parstack,
						     $safeeval,'src');
	if ($constructtag) { $result = &Apache::edit::rebuild_tag($token); }
    }
    return $result;
}

sub end_allow {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    if ( $target eq 'edit') { return (&Apache::edit::end_table()); }
    return '';
}

#-- Frames (end tag required)
#-- <frameset>
sub start_frameset {
    my ($target,$token) = @_;
    my $currentstring = '';	# Close any pending para.
    if ($target eq 'web' || $target eq 'webgrade') { 
	$currentstring = 
	    &Apache::loncommon::start_page($Apache::londefdef::title,
					   $Apache::londefdef::head,
					   {'add_entries'    => $token->[2],
					    'no_title'       => 1,
					    'force_register' => 1,
					    'frameset'       => 1,});

    }
    return $currentstring;
}

sub end_frameset {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];
    }
    return $currentstring;
}

#-- <xmp> (end tag required)
sub start_xmp {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '\begin{verbatim}';
    } 
    return $currentstring;
}

sub end_xmp {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '\end{verbatim}';
    }
    return $currentstring;
}

#-- <pre> (end tag required)
sub start_pre {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = &end_p();	# close off pending <p>
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];
    } elsif ($target eq 'tex') {
	$currentstring .= '\begin{verbatim}';
	&Apache::lonxml::disable_LaTeX_substitutions();
    } 
    return $currentstring;
}

sub end_pre {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring .= '\end{verbatim}';
	&Apache::lonxml::enable_LaTeX_substitutions();
    }
    return $currentstring;
}

#-- <insert>
sub start_insert {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	my $display = &Apache::lonxml::get_param('display',$parstack,$safeeval,undef,1);
	$currentstring .= '<b>'.$display.'</b>';;
    }
    return $currentstring;
}

sub end_insert {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= '';
    }
    return $currentstring;
}

#-- <externallink>
sub start_externallink {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	my $display = &Apache::lonxml::get_param('display',$parstack,$safeeval,undef,1);
	$currentstring .= '<b>'.$display.'</b>';;
    }
    return $currentstring;
}

sub end_externallink {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= '';
    }
    return $currentstring;
}

#-- <blankspace heigth="">
sub start_blankspace {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = &end_p();	# closes off any unclosed <p>
    if ($target eq 'tex') {
	my $howmuch = &Apache::lonxml::get_param('heigth',$parstack,$safeeval,undef,1);
	$currentstring .= '\vskip '.$howmuch.' ';
    }
    return $currentstring;
}

sub end_blankspace {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'tex') {
	$currentstring .= '';
    }
    return $currentstring;
}

#-- <abbr> tag (end tag required)
sub start_abbr {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_abbr {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <acronym> tag (end tag required)
sub start_acronym {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_acronym {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <area> tag (end tag forbidden)
sub start_area {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_area {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <base> tag (end tag forbidden)
sub start_base {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    }
    return $currentstring;
}

sub end_base {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <bdo> tag (end tag required)
sub start_bdo {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_bdo {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <bgsound> tag (end tag optional)
sub start_bgsound {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_bgsound {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <blink> tag (end tag required)
sub start_blink {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_blink {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <blockquote> tag (end tag required)
sub start_blockquote {
    my ($target,$token) = @_;
    my $currentstring = &end_p();	# Close any unclosed <p>
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];     
    } 
    if ($target eq 'tex') {
	$currentstring .= '\begin{quote}';
    }
    return $currentstring;
}

sub end_blockquote {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    if ($target eq 'tex') {
	$currentstring = '\end{quote}';
    }
    return $currentstring;
}

#-- <button> tag (end tag required)
sub start_button {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_button {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <caption> tag (end tag required)
sub start_caption {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_caption {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <col> tag (end tag forbdden)
sub start_col {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_col {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <colgroup> tag (end tag optional)
sub start_colgroup {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_colgroup {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <del> tag (end tag required)
sub start_del {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_del {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <fieldset> tag (end tag required)
sub start_fieldset {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_fieldset {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <frame> tag (end tag forbidden)
sub start_frame {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_frame {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <iframe> tag (end tag required)
sub start_iframe {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_iframe {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <ins> tag (end tag required)
sub start_ins {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_ins {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <isindex> tag (end tag forbidden)
sub start_isindex {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_isindex {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <keygen> tag (end tag forbidden)
sub start_keygen {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_keygen {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <label> tag
sub start_label {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_label {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <layer> tag (end tag required)
sub start_layer {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_layer {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <legend> tag (end tag required)
sub start_legend {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_legend {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <link> tag (end tag forbidden)
sub start_link {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	my $href=&Apache::lonxml::get_param('href',$parstack,$safeeval,
					    undef,1);
	&Apache::lonxml::extlink($href);
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_link {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <marquee> tag (end tag optional)
sub start_marquee {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_marquee {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <multicol> tag (end tag required)
sub start_multicol {
    my ($target,$token) = @_;
    my $currentstring = &end_p();	# Close any pending <p>
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];     
    } 
    return $currentstring;
}

sub end_multicol {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <nobr> tag (end tag required)
sub start_nobr {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    }  elsif ($target eq 'tex') {
	$currentstring='\mbox{';
    }
    return $currentstring;
}

sub end_nobr {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    }   elsif ($target eq 'tex') {
	$currentstring='}';
    }
    return $currentstring;
}

#-- <noembed> tag (end tag required)
sub start_noembed {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_noembed {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <noframes> tag (end tag required)
sub start_noframes {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_noframes {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <nolayer> tag (end tag required)
sub start_nolayer {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_nolayer {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <noscript> tag (end tag required)
sub start_noscript {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_noscript {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <object> tag (end tag required)
sub start_object {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_object {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <optgroup> tag (end tag required)
sub start_optgroup {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_optgroup {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <samp> tag (end tag required)
sub start_samp {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } elsif ($target eq 'tex') {
	$currentstring='\texttt{';
    }
    return $currentstring;
}

sub end_samp {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } elsif ($target eq 'tex') {
	$currentstring='}';
    }
    return $currentstring;
}

#-- <server> tag
sub start_server {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_server {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <spacer> tag (end tag forbidden)
sub start_spacer {
    my ($target,$token) = @_;
    my $currentstring = &end_p();	# Close off any open <p> tag.
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring .= $token->[4];     
    } 
    return $currentstring;
}

sub end_spacer {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <span> tag (end tag required)
sub start_span {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_span {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <tbody> tag (end tag optional)
sub start_tbody {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_tbody {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <tfoot> tag (end tag optional)
sub start_tfoot {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_tfoot {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <thead> tag (end tag optional)
sub start_thead {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_thead {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <var> tag
sub start_var {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } elsif ($target eq 'tex') {
	$currentstring = '\textit{'; 
    }
    return $currentstring;
}

sub end_var {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];
    } elsif ($target eq 'tex') {
	$currentstring = '}'; 
    } 
    return $currentstring;
}

#-- <wbr> tag (end tag forbidden)
sub start_wbr {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[4];     
    } 
    return $currentstring;
}

sub end_wbr {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = $token->[2];    
    } 
    return $currentstring;
}

#-- <hideweboutput> tag
sub start_hideweboutput {
    my ($target,$token) = @_;
    if ($target eq 'web' || $target eq 'webgrade') {
	&Apache::lonxml::startredirection();     
    } 
    return '';
}

sub end_hideweboutput {
    my ($target,$token) = @_;
    my $currentstring = '';
    if ($target eq 'web' || $target eq 'webgrade') {
	$currentstring = &Apache::lonxml::endredirection();    
    } 
    return '';
}


sub image_replication {
    my $src = shift;
    if (not -e $src) { &Apache::lonnet::repcopy($src); }
    #replicates eps or ps 
    my $epssrc = my $pssrc = $src;
    $epssrc =~ s/\.(gif|jpg|jpeg|png)$/.eps/i;
    $pssrc  =~ s/\.(gif|jpg|jpeg|png)$/.ps/i;
    if (not -e $epssrc && not -e $pssrc) {
	my $result=&Apache::lonnet::repcopy($epssrc);
	if ($result ne 'ok') { &Apache::lonnet::repcopy($pssrc); }
    }
    return '';
}
#
#   Get correct sizing parameter for an image given
#   it's initial ht. and wid.  This allows sizing of
#   images that are generated on-the-fly (e.g. gnuplot)
#   as well as serving as a utility for image_size.
# 
#  Parameter:
#        height_param
#        width_param    - Initial picture dimensions.
#        scaling        - A scale factor.
#        parstack,      - the current stack of tag attributes 
#                         from the xml parser
#        safeeval,      - pointer to the safespace
#        depth,         - from what level in the stack to look for attributes
#                         (assumes -1 if unspecified)
#        cis            - look for attrubutes case insensitively
#                         (assumes false)
#
# Returns:
#   height, width   - new dimensions.
#
sub resize_image {
    my ($height_param, $width_param, $scaling,
	$parstack, $safeeval, $depth, $cis) = @_;

    # First apply the scaling...

    $height_param = $height_param * $scaling;
    $width_param  = $width_param  * $scaling;

    #do we have any specified LaTeX size of the picture?
    my $toget='TeXwidth'; 
    if ($cis) { 
	$toget=lc($toget); 
    }
    my $TeXwidth = &Apache::lonxml::get_param($toget,$parstack,
					      $safeeval,$depth,$cis);
    $toget='TeXheight'; if ($cis) { $toget=lc($toget); }
    my $TeXheight = &Apache::lonxml::get_param($toget,$parstack,
					       $safeeval,$depth,$cis);
    #do we have any specified web size of the picture?
    my $width = &Apache::lonxml::get_param('width',$parstack,$safeeval,
					   $depth,1);
    if ($TeXwidth) { 
	my $old_width_param=$width_param;
	if ($TeXwidth=~/(\d+)\s*\%/) {
	    $width_param = $1*$env{'form.textwidth'}/100;
	} else { 
	    $width_param = $TeXwidth;
	}
	if ($TeXheight) {
	    $height_param = $TeXheight;
	} elsif ($old_width_param) {
	    $height_param=$TeXwidth/$old_width_param*$height_param;
	}
    } elsif ($TeXheight) {
	$height_param = $TeXheight;
	if ($height_param) {
	    $width_param  = $TeXheight/$height_param*$width_param;
	}
    } elsif ($width) {
	my $old_width_param=$width_param;
	$width_param = $width*$scaling;
	if ($old_width_param) {
	    $height_param=$width_param/$old_width_param*$height_param;
	}
    }
    if ($width_param > $env{'form.textwidth'}) {
        my $old_width_param=$width_param;
	$width_param =0.95*$env{'form.textwidth'};
	if ($old_width_param) {
	    $height_param=$width_param/$old_width_param*$height_param;
	}
    }

    return ($height_param, $width_param);
}

sub image_size {
    my ($src,$scaling,$parstack,$safeeval,$depth,$cis)=@_;

    #size of image from gif/jpg/jpeg/png 
    my $ressrc=&Apache::lonnet::filelocation($Apache::lonxml::pwd[-1],$src);
    if (-e $ressrc) {
	$src = $ressrc;
    }
    my $image = Image::Magick->new;
    my $current_figure = $image->Read($src);
    my $width_param = $image->Get('width');
    my $height_param = $image->Get('height');
    &Apache::lonxml::debug("Image magick says: $src :  Height = $height_param width = $width_param");
    undef($image);

    ($height_param, $width_param) = &resize_image($height_param, $width_param,
						  $scaling, $parstack, $safeeval, 
						  $depth, $cis);

    return ($height_param, $width_param);
}

sub image_width {
    my ($height, $width) = &image_size(@_);
    return $width;
}
#  Not yet 100% sure this is correct in all circumstances..
#  due to my uncertainty about mods to image_size.
#
sub image_height {
    my ($height, $width) = &image_size(@_);
    return $height;
}

sub get_eps_image {
    my ($src)=@_;
    my $orig_src=&Apache::lonnet::filelocation($Apache::lonxml::pwd[-1], $src);

    # In order to prevent the substitution of the alt text, we need to
    # be sure the orig_src file is on system now so:

    if (! -e $orig_src) {
	&Apache::lonnet::repcopy($orig_src); # Failure is not completely fatal.
    }
    &Apache::lonxml::debug("get_eps_image: Original image: $orig_src");
    my ($spath, $sname, $sext) = &fileparse($src, qr/\.(bmp|gif|png|jpg|jpeg)/i);
    $src=~s/\.(bmp|gif|png|jpg|jpeg)$/\.eps/i;
    $src=&Apache::lonnet::filelocation($Apache::lonxml::pwd[-1],$src);
    &Apache::lonxml::debug("Filelocation gives: $src");
    if (! -e $src) {
	&Apache::lonxml::debug("$src does not exist");
	if (&Apache::lonnet::repcopy($src) ne 'ok' ) {
	    &Apache::lonxml::debug("Repcopy of $src failed (1)");
	    #if replication failed try to find ps file
	    $src=~s/\.eps$/\.ps/;
	    &Apache::lonxml::debug("Now looking for $src");
	    #if no ps file try to replicate it.
	    my $didrepcopy = &Apache::lonnet::repcopy($src);
	    &Apache::lonxml::debug("repcopy of $src ... $didrepcopy");
	    if ( (not -e $src) ||
		($didrepcopy ne 'ok')) {
		&Apache::lonxml::debug("Failed to find or replicate $src");

		#if replication failed try to produce eps file dynamically
		$src=~s/\.ps$/\.eps/;
		my $temp_file;
		open(FILE,">>/home/httpd/prtspool/$env{'user.name'}_$env{'user.domain'}_printout.dat");
		my $newsrc=$orig_src;
		$newsrc =~ s|(.*)/res/|/home/httpd/html/res/|;
		&Apache::lonxml::debug("queueing $newsrc for dynamic eps production.");
		print FILE ("$newsrc\n");
		close(FILE);
		$src=~s|/home/httpd/html/res|/home/httpd/prtspool|;
		$src=~s|/home/([^/]*)/public_html/|/home/httpd/prtspool/$1/|;
		if ($sext ne "") {	 # Put the ext. back in to uniquify.
		    $src =~ s/\.eps$/$sext.eps/;
		}

	    }

	}
    } else {
	# If the postscript file has spaces in its name,
	# LaTeX will gratuitiously vomit.  Therefore
	# queue such files for copy with " " replaced by "_".
	# printout.pm will know them by their .ps  or .eps extensions.
	my $newsrc = $orig_src;
	$newsrc    =~  s|(.*)/res/|/home/httpd/html/res/|;
	open(FILE,">>/home/httpd/prtspool/$env{'user.name'}_$env{'user.domain'}_printout.dat");
	print FILE "$src\n";
	close FILE;
	$src=~s|/home/httpd/html/res|/home/httpd/prtspool|;
	$src=~s|/home/([^/]*)/public_html/|/home/httpd/prtspool/$1/|;
    }
    my ($path,$file)=($src=~m|(.*)/([^/]*)$|);
    $path =~ s/ /\_/g;
    $file =~ s/ /\_/g;
    &Apache::lonxml::debug("get_eps_image returning: $path / $file<BR />");
    return ($path.'/',$file);
}

sub eps_generation {
    my ($src,$file,$width_param) = @_;	     
    my $filename = "/home/httpd/prtspool/$env{'user.name'}_$env{'user.domain'}_printout.dat";
    my $temp_file = Apache::File->new('>>'.$filename); 
    print $temp_file "$src\n";
    my $newsrc = $src;
    $newsrc =~ s/(\.bmp|\.gif|\.jpg|\.jpeg)$/\.eps/i;
    $newsrc=~s{/home/httpd/html/res}{};
    $newsrc=~s{/home/($LONCAPA::username_re)/public_html/}{/$1/};
    $newsrc=~s{/\./}{/};
    $newsrc=~s{/([^/]+)\.(ps|eps)}{/};
    if ($newsrc=~m{/home/httpd/lonUsers/}) {
	$newsrc=~s{/home/httpd/lonUsers}{};
	$newsrc=~s{/($LONCAPA::domain_re)/./././}{/$1/};
    }
    if ($newsrc=~m{/userfiles/}) {
	return ' \graphicspath{{'.$newsrc.'}}\includegraphics[width='.$width_param.' mm]{'.$file.'} ';
    } else {
	return ' \graphicspath{{/home/httpd/prtspool'.$newsrc.'}}\includegraphics[width='.$width_param.' mm]{'.$file.'} ';
    }
}

sub file_path {     
    my $src=shift;
    my ($file,$path); 
    if ($src =~ m!(.*)/([^/]*)$!) {
	$file = $2; 
	$path = $1.'/'; 
    } 
    return $file,$path;
}
#  Converts a measurement in to mm from any of 
#  the other valid LaTeX units of measure.
#  If the units of measure are missing from the 
#  parameter, it is assumed to be in and returned
#  with mm units of measure
sub recalc {
    my $argument = shift;
    if (not $argument=~/(mm|cm|in|pc|pt)/) {return $argument.' mm';}
    $argument=~/\s*(\d+\.?\d*)\s*(mm|cm|in|pc|pt)/;
    my $value=$1;
    my $units=$2;
    if ($units eq 'cm') {
	$value*=10;
    } elsif ($units eq 'in') {
	$value*=25.4;
    } elsif ($units eq 'pc') {
	$value*=(25.4*12/72.27);
    } elsif ($units eq 'pt') {
	$value*=(25.4/72.27);
    }
    return $value.' mm';
}

sub LATEX_length {
    my $garbage=shift;
    $garbage=~s/^\s+$//;
    $garbage=~s/^\s+(\S.*)/$1/;#space before 
    $garbage=~s/(.*\S)\s+$/$1/;#space after 
    $garbage=~s/(\s)+/$1/;#only one space
    $garbage=~s/(\\begin{([^\}]+)}|\\end{([^\}]+)})//g;#remove LaTeX \begin{...} and \end{...}
    $garbage=~s/(\$\_\{|\$\_|\$\^{|\$\^|\}\$)//g;#remove $_{,$_,$^{,$^,}$
    $garbage=~s/([^\\])\$/$1/g;#$
    $garbage=~s/(\\ensuremath\{\_\{|\\ensuremath\{\_|\\ensuremath\{\^{|\\ensuremath\{\^|\})//g;#remove \ensuremath{...}
   $garbage=~s/(\\alpha|\\beta|\\gamma|\\delta|\\epsilon|\\verepsilon|\\zeta|\\eta|\\theta|\\vartheta|\\iota|\\kappa|\\lambda|\\mu|\\nu|\\xi|\\pi|\\varpi|\\rho|\\varrho|\\sigma|\\varsigma|\\tau|\\upsilon|\\phi|\\varphi|\\chi|\\psi|\\omega|\\Gamma|\\Delta|\\Theta|\\Lambda|\\Xi|\\Pi|\\Sigma|\\Upsilon|\\Phi|\\Psi|\\Omega)/1/g;
    $garbage=~s/(\\pm|\\mp|\\times|\\div|\\cdot|\\ast|\\star|\\dagger|\\ddagger|\\amalg|\\cap|\\cup|\\uplus|\\sqcap|\\sqcup|\\vee|\\wedge|\\oplus|\\ominus|\\otimes|\\circ|\\bullet|\\diamond|\\lhd|\\rhd|\\unlhd|\\unrhd|\\oslash|\\odot|\\bigcirc|\\Box|\\Diamond|\\bigtriangleup|\\bigtriangledown|\\triangleleft|\\triangleright|\\setminus|\\wr)/1/g;
    $garbage=~s/(\\le|\\ll|\\leq|\\ge|\\geq|\\gg|\\neq|\\doreq|\\sim|\\simeq|\\subset|\\subseteq|\\sqsubset|\\sqsubseteq|\\in|\\vdash|\\models|\\supset|\\supseteq|\\sqsupset|\\sqsupseteq|\\ni|\\dash|\\perp|\\approx|\\cong|\\equiv|\\propto|\\prec|\\preceq|\\parallel|\\asymp|\\smile|\\frown|\\bowtie|\\succ|\\succeq|\\mid)/1/g;
    $garbage=~s/(\\not<|\\\\not\\le|\\not\\prec|\\not\\preceq|\\not\\subset|\\not\\subseteq|\\not\\sqsubseteq|\\not\\in|\\not>|\\not\\ge|\\not\\succ|\\notsucceq|\\not\\supset|\\notsupseteq|\\not\\sqsupseteq|\\notin|\\not=|\\not\\equiv|\\not\\sim|\\not\\simeq|\\not\\approx|\\not\\cong|\\not\\asymp)/1/g;
    $garbage=~s/(\\leftarrow|\\gets|\\Leftarrow|\\rightarrow|\\to|\\Rightarrow|\\leftrightarrow|\\Leftrightarrow|\\mapsto|\\hookleftarrow|\\leftharpoonup|\\leftkarpoondown|\\rightleftharpoons|\\longleftarrow|\\Longleftarrow|\\longrightarrow|\\Longrightarrow|\\longleftrightarrow|\\Longleftrightarrow|\\longmapsto|\\hookrightarrow|\\rightharpoonup|\\rightharpoondown|\\uparrow|\\Uparrow|\\downarrow|\\Downarrow|\\updownarrow|\\Updownarrow|\\nearrow|\\searrow|\\swarrow|\\nwarrow)/11/g;
    $garbage=~s/(\\aleph|\\hbar|\\imath|\\jmath|\\ell|\\wp|\\Re|\\Im|\\mho|\\prime|\\emptyset|\\nabla|\\surd|\\partial|\\top|\\bot|\\vdash|\\dashv|\\forall|\\exists|\\neg|\\flat|\\natural|\\sharp|\\\||\\angle|\\backslash|\\Box|\\Diamond|\\triangle|\\clubsuit|\\diamondsuit|\\heartsuit|\\spadesuit|\\Join|\\infty)/11/g;
    $garbage=~s/(\\hat{([^}]+)}|\\check{([^}]+)}|\\dot{([^}]+)}|\\breve{([^}]+)}|\\acute{([^}]+)}|\\ddot{([^}]+)}|\\grave{([^}]+)}|\\tilde{([^}]+)}|\\mathring{([^}]+)}|\\bar{([^}]+)}|\\vec{([^}]+)})/$1/g;
    #remove some other LaTeX command
    $garbage=~s|\\(\w+)\\|\\|g;	 
    $garbage=~s|\\(\w+)(\s*)|$2|g;	 	 
    $garbage=~s|\+|11|g;
    my  $value=length($garbage);
    return $value;
}

#   Wrap image 'stuff' inside of the LaTeX required to implement 
#   alignment:
#     align_tex_image(align, latex_rendering, image)
#   Where:
#     align   - The HTML alignment specification.
#     latex_rendering - rendering hint for latex.
#     image   - The LaTeX needed to insert the image itsef.
#     width,height - dimensions of the image.
# Returns:
#    The 1/2 wrapped image and the stuff required to close the
#    wrappage.  This allows e.g. randomlabel to insert more stuff
#    into the closure.
#
sub align_latex_image {
    my ($align, $latex_rendering, $image, $width, $height) = @_;
    my $currentstring;        # The 1/2 wrapped image.
    my $closure;              # The closure of the wrappage.

    # if it's none just return it back
    if ($latex_rendering eq 'none') {
	return ($image,'');
    }

    #    If there's an alignment specification we need to honor it here.
    #    For the horizontal alignments, we will also honor the
    #    value of the latex specfication.  The default is parbox,
    #    and that's used for illegal values too.  
    #    
    #    Even though we set a default alignment value, the user
    #    could have given us an illegal value.  In that case we
    #    just use the default alignment of bottom..
    $currentstring = "\n% figurewrapping \n";
    if      ($align eq "top")    {
	$currentstring .= '\raisebox{-'.$height.'mm}{'.$image;
	$closure = '}';
    } elsif (($align eq "center") || ($align eq "middle")) { # Being kind
	my $offset = $height/2;
	$currentstring .= '\raisebox{-'.$offset.'mm}{'.$image;
	$closure       = '}';
    } elsif ($align eq "left")   { 
	if ($latex_rendering eq "parpic") { 
	    $currentstring .= '\parpic[l]{'.$image;
	    $closure       = '}';
	} elsif ($latex_rendering eq "parbox") {
	    $currentstring .= '\begin{minipage}[l]{'.$width.'mm}'
		.$image;
	    $closure = '\end{minipage}';
	} elsif ($latex_rendering eq "wrapfigure"
		 || $latex_rendering ne 'none') {  # wrapfig render
	    $currentstring .= 
		'\begin{wrapfigure}{l}{'.$width.'mm}'
		.'\scalebox{1.0}{'.$image;
	    $closure = '}\end{wrapfigure}';
	}
    } elsif ($align eq "right")  {   
	if ($latex_rendering eq "parpic") {
	    $currentstring .= '\parpic[r]{'.$image;
	    $closure = '}';
	} elsif ($latex_rendering eq "parbox") {
	    $currentstring .=  '\begin{minipage}[r]{'.$width.'mm}'
		.$image;
	    $closure = '\end{minipage}';
	} elsif ($latex_rendering eq "wrapfigure"
		 || $latex_rendering ne 'none') {  # wrapfig render
	    $currentstring .= 
		'\begin{wrapfigure}{r}{'.$width.'mm}'
		.'\scalebox{1.0}{'.$image;
	    $closure = '}\end{wrapfigure}';
	}
    } else {		# Bottom is also default.
	# $currentstring = '\raisebox{'.$height.'mm}{'.$image.'}';
	$currentstring .= "{$image";
	$closure       = '}';
    }
    $currentstring .= "\n% end wrappage\n";
    $closure        = "\n% Begin closure\n".$closure."\n% End closure\n";
    return ($currentstring, $closure);
}

# is_inside_of $tagstack $tag
#    This sub returns true if the current state of Xml processing
#    is inside of the tag.   
# Parameters:
#     tagstack   - The tagstack from the parser.
#     tag        - The tag (without the <>'s.).
# Sample usage:
#     if (is_inside_of($tagstack "table")) {
#          # I'm in a table....
#      }
sub is_inside_of {
    my ($tagstack, $tag) = @_;
    my @stack = @$tagstack;
    for (my $i = ($#stack - 1); $i >= 0; $i--) {
	if ($stack[$i] eq $tag) {
	    return 1;
	}
    }
    return 0;
}


1;
__END__