--- loncom/interface/slotrequest.pm	2005/11/14 23:21:55	1.30
+++ loncom/interface/slotrequest.pm	2006/02/06 22:42:11	1.45
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Handler for requesting to have slots added to a students record
 #
-# $Id: slotrequest.pm,v 1.30 2005/11/14 23:21:55 albertel Exp $
+# $Id: slotrequest.pm,v 1.45 2006/02/06 22:42:11 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -47,8 +47,7 @@ sub fail {
 	$r->print('<p>'.&mt('Failed.').'</p>');
     }
     
-    $r->print('<p><a href="/adm/flip?postdata=return:">'.
-	      &mt('Return to last resource').'</a></p>');
+    &return_link($r);
     &end_page($r);
 }
 
@@ -89,7 +88,9 @@ sub get_reservation_ids {
 
     my %consumed=&Apache::lonnet::dump('slot_reservations',$cdom,$cnum,
 				       "^$slot_name\0");
-    
+    if (&network_error(%consumed)) { 
+	return 'error: Unable to determine current status';
+    }
     my ($tmp)=%consumed;
     if ($tmp=~/^error: 2 / ) {
 	return 0;
@@ -111,7 +112,7 @@ sub space_available {
 }
 
 sub check_for_reservation {
-    my ($symb)=@_;
+    my ($symb,$mode)=@_;
     my $student = &Apache::lonnet::EXT("resource.0.availablestudent", $symb,
 				       $env{'user.domain'}, $env{'user.name'});
 
@@ -124,7 +125,19 @@ sub check_for_reservation {
     my ($cnum,$cdom)=&get_course();
     my %slots=&Apache::lonnet::get('slots', [@slots], $cdom, $cnum);
 
-    foreach my $slot_name (@slots) {
+    if (&network_error($student) || &network_error($course)  ||
+	&network_error(%slots)) {
+	return 'error: Unable to determine current status';
+    }    
+    my @got;
+    foreach my $slot_name (sort {
+	if (ref($slots{$a}) && ref($slots{$b})) {
+	    return $slots{$a}{'starttime'} <=> $slots{$b}{'starttime'}
+	}
+	if (ref($slots{$a})) { return -1;}
+	if (ref($slots{$b})) { return 1;}
+	return 0;
+    } @slots) {
 	next if (!defined($slots{$slot_name}) ||
 		 !ref($slots{$slot_name}));
 	&Apache::lonxml::debug(time." $slot_name ".
@@ -133,29 +146,51 @@ sub check_for_reservation {
 	if ($slots{$slot_name}->{'endtime'} > time &&
 	    $slots{$slot_name}->{'startreserve'} < time) {
 	    # between start of reservation times and end of slot
-	    return($slot_name, $slots{$slot_name});
+	    if ($mode eq 'allslots') {
+		push(@got,$slot_name);
+	    } else {
+		return($slot_name, $slots{$slot_name});
+	    }
 	}
     }
+    if ($mode eq 'allslots' && @got) {
+	return @got;
+    }
     return (undef,undef);
 }
 
 sub check_for_conflict {
-    my ($symb,$new_slot_name)=@_;
+    my ($symb,$new_slot_name,$new_slot,$slots)=@_;
+
+    if (!defined($new_slot->{'uniqueperiod'})) { return undef; }
+
     my $student = &Apache::lonnet::EXT("resource.0.availablestudent", $symb,
 				       $env{'user.domain'}, $env{'user.name'});
-    my $course = &Apache::lonnet::EXT("resource.0.available", $symb,
-				      $env{'user.domain'}, $env{'user.name'});
+    my $course =  &Apache::lonnet::EXT("resource.0.available",        $symb,
+				       $env{'user.domain'}, $env{'user.name'});
     my @slots = (split(/:/,$student), split(/:/, $course));
     my ($cnum,$cdom)=&get_course();
-    my %slots=&Apache::lonnet::get('slots', [@slots], $cdom, $cnum);
+    if (!ref($slots)) {
+	my %slots=&Apache::lonnet::get('slots', [@slots], $cdom, $cnum);
+	$slots = \%slots;
+    }
+
+    if (&network_error($student) || &network_error($course)  ||
+	&network_error(%$slots)) {
+	return 'error: Unable to determine current status';
+    }    
+
+    my ($new_uniq_start,$new_uniq_end) = @{$new_slot->{'uniqueperiod'}};
     foreach my $slot_name (@slots) {
-	next if (!defined($slots{$slot_name}) ||
-		 !ref($slots{$slot_name}));
+	next if (!defined($slots->{$slot_name}) ||
+		 !ref($slots->{$slot_name}));
 
-        next if (!defined($slots{$slot_name}->{'uniqueperiod'}) ||
-		 !ref($slots{$slot_name}->{'uniqueperiod'}));
-	my ($start,$end)=@{$slots{$slot_name}->{'uniqueperiod'}};
-	if ($start<time && time < $end) {
+        next if (!defined($slots->{$slot_name}{'uniqueperiod'}) ||
+		 !ref($slots->{$slot_name}{'uniqueperiod'}));
+	my ($start,$end)=@{$slots->{$slot_name}{'uniqueperiod'}};
+	if (!
+	    ($start < $new_uniq_start &&  $end < $new_uniq_start) ||
+	    ($start > $new_uniq_end   &&  $end > $new_uniq_end  )) {
 	    return $slot_name;
 	}
     }
@@ -163,6 +198,14 @@ sub check_for_conflict {
 
 }
 
+sub network_error {
+    my ($result) = @_;
+    if ($result =~ /^(con_lost|no_such_host|error: [^2])/) {
+	return 1;
+    }
+    return 0;
+}
+
 sub make_reservation {
     my ($slot_name,$slot,$symb)=@_;
 
@@ -171,11 +214,17 @@ sub make_reservation {
     my $value=&Apache::lonnet::EXT("resource.0.availablestudent",$symb,
 				   $env{'user.domain'},$env{'user.name'});
     &Apache::lonxml::debug("value is  $value<br />");
+    if (&network_error($value)) { 
+	return 'error: Unable to determine current status';
+    }
+
     foreach my $other_slot (split(/:/, $value)) {
 	if ($other_slot eq $slot_name) {
 	    my %consumed=&Apache::lonnet::dump('slot_reservations', $cdom,
 					       $cnum, "^$slot_name\0");   
-
+	    if (&network_error($value)) { 
+		return 'error: Unable to determine current status';
+	    }
 	    my $me=$env{'user.name'}.'@'.$env{'user.domain'};
 	    foreach my $key (keys(%consumed)) {
 		if ($consumed{$key}->{'name'} eq $me) {
@@ -190,7 +239,9 @@ sub make_reservation {
     if (!defined($max)) { $max=99999; }
 
     my (@ids)=&get_reservation_ids($slot_name);
-
+    if (&network_error(@ids)) { 
+	return 'error: Unable to determine current status';
+    }
     my $last=0;
     foreach my $id (@ids) {
 	my $num=(split('\0',$id))[1];
@@ -231,17 +282,64 @@ sub make_reservation {
     return undef;
 }
 
+sub remove_registration {
+    my ($r) = @_;
+    my $name = &Apache::loncommon::plainname($env{'form.uname'},
+					     $env{'form.udom'});
+
+    my $title = &Apache::lonnet::gettitle($env{'form.symb'});
+
+    my $hidden_input;
+    foreach my $parm ('uname','udom','slotname','entry','symb') {
+	$hidden_input .=
+	    '<input type="hidden" name="'.$parm.'" value="'
+	    .&HTML::Entities::encode($env{'form.'.$parm},'"<>&\'').'" />'."\n";
+    }
+    $r->print(<<"END_CONFIRM");
+<p> Remove $name from slot $env{'form.slotname'} for $title</p>
+<form action="/adm/slotrequest" method="POST">
+    <input type="hidden" name="command" value="release" />
+    $hidden_input
+    <input type="submit" name="Yes" value="yes" />
+</form>
+<form action="/adm/slotrequest" method="POST">
+    <input type="hidden" name="command" value="showslots" />
+    <input type="submit" name="No" value="no" />
+</form>
+END_CONFIRM
+
+}
+
 sub release_slot {
-    my ($r,$symb,$slot_name,$inhibit_return_link)=@_;
+    my ($r,$symb,$slot_name,$inhibit_return_link,$mgr)=@_;
 
     if ($slot_name eq '') { $slot_name=$env{'form.slotname'}; }
     my ($cnum,$cdom)=&get_course();
 
+    my ($uname,$udom) = ($env{'user.name'}, $env{'user.domain'});
+    if ($mgr eq 'F' 
+	&& defined($env{'form.uname'}) && defined($env{'form.udom'})) {
+	($uname,$udom) = ($env{'form.uname'}, $env{'form.udom'});
+    }
+
+    if ($mgr eq 'F' 
+	&& defined($env{'form.symb'})) {
+	$symb = $env{'form.symb'};
+    }
+    my %slot=&Apache::lonnet::get_slot($slot_name);
+    my $description=&get_description($env{'form.slotname'},\%slot);
+
+    if ($mgr ne 'F') {
+	if ($slot{'starttime'} < time) {
+	    $r->print("<p>Not allowed to release Reservation: $description, as it has already ended.  </p>");
+	    &return_link($r);
+	    return 0;
+	}
+    }
     # get parameter string, check for existance, rebuild string with the slot
-				       
     my @slots = split(/:/,&Apache::lonnet::EXT("resource.0.availablestudent",
-					       $symb,$env{'user.domain'},
-					       $env{'user.name'}));
+					       $symb,$udom,$uname));
+
     my @new_slots;
     foreach my $exist_slot (@slots) {
 	if ($exist_slot eq $slot_name) { next; }
@@ -253,32 +351,76 @@ sub release_slot {
     my %consumed=&Apache::lonnet::dump('slot_reservations',$cdom,$cnum,
 				       "^$slot_name\0");
     foreach my $entry (keys(%consumed)) {
-	if ( $consumed{$entry}->{'name'} eq 
-	     ($env{'user.name'}.'@'.$env{'user.domain'}) ) {
+	if ( $consumed{$entry}->{'name'} eq ($uname.'@'.$udom) ) {
 	    &Apache::lonnet::del('slot_reservations',[$entry],
 				 $cdom,$cnum);
 	}
     }
+
     # store new parameter string
     my $result=&Apache::lonparmset::storeparm_by_symb($symb,
 						      '0_availablestudent',
 						      1, $new_param, 'string',
-						      $env{'user.name'},
-						      $env{'user.domain'});
-    my %slot=&Apache::lonnet::get_slot($slot_name);
-    my $description=&get_description($env{'form.slotname'},\%slot);
+						      $uname,$udom);
     $r->print("<p>Released Reservation: $description</p>");
-    if (!$inhibit_return_link) {
-	$r->print('<p><a href="/adm/flip?postdata=return:">'.
-		  &mt('Return to last resource').'</a></p>');
+    if ($mgr eq 'F') {
+	$r->print('<p><a href="/adm/slotrequest?command=showslots">'.
+		  &mt('Return to slot list').'</a></p>');
     }
+    if (!$inhibit_return_link) { &return_link($r);  }
     return 1;
 }
 
+sub delete_slot {
+    my ($r)=@_;
+
+    my $slot_name = $env{'form.slotname'};
+    my %slot=&Apache::lonnet::get_slot($slot_name);
+
+    my ($cnum,$cdom)=&get_course();
+    my %consumed=&Apache::lonnet::dump('slot_reservations',$cdom,$cnum,
+				       "^$slot_name\0");
+    my ($tmp) = %consumed;
+    if ($tmp =~ /error: 2/) { undef(%consumed); }
+
+    if (%slot && !%consumed) {
+	$slot{'type'} = 'deleted';
+	my $ret = &Apache::lonnet::cput('slots', {$slot_name => \%slot},
+					$cdom, $cnum);
+	if ($ret eq 'ok') {
+	    $r->print("<p>Slot <tt>$slot_name</tt> marked as deleted.</p>");
+	} else {
+	    $r->print("<p> An error ($ret) occurse when attempting to delete Slot <tt>$slot_name</tt>.</p>");
+	}
+    } else {
+	if (%consumed) {
+	    $r->print("<p>Slot <tt>$slot_name</tt> has active reservations.</p>");
+	} else {
+	    $r->print("<p>Slot <tt>$slot_name</tt> does not exist.</p>");
+	}
+    }
+    $r->print('<p><a href="/adm/slotrequest?command=showslots">'.
+	      &mt('Return to slot list').'</a></p>');
+    &return_link($r);
+}
+
+sub return_link {
+    my ($r) = @_;
+    $r->print('<p><a href="/adm/flip?postdata=return:">'.
+	      &mt('Return to last resource').'</a></p>');
+}
+
 sub get_slot {
     my ($r,$symb)=@_;
 
-    my $slot_name=&check_for_conflict($symb,$env{'form.slotname'});
+    my %slot=&Apache::lonnet::get_slot($env{'form.slotname'});
+    my $slot_name=&check_for_conflict($symb,$env{'form.slotname'},\%slot);
+
+    if ($slot_name =~ /^error: (.*)/) {
+	$r->print("<p>An error occured while attempting to make a reservation. ($1)</p>");
+	&return_link($r);
+	return;
+    }
     if ($slot_name) {
 	my %slot=&Apache::lonnet::get_slot($slot_name);
 	my $description1=&get_description($slot_name,\%slot);
@@ -299,33 +441,30 @@ STUFF
 STUFF
 	    $r->print(' your reservation from <b>'.$description1.'</b> to <b>'.
 		      $description2.
-		      '</b> <br />or <a href="/adm/flip?postdata=return:">'.
-		      &mt('Return to last resource').'</a></p>');
+		      '</b> <br />or </p>');
+	    &return_link($r);
 	    $r->print(<<STUFF);
 </form>
 STUFF
         } else {
-	    $r->print('<p><a href="/adm/flip?postdata=return:">'.
-		      &mt('Return to last resource').'</a></p>');
+	    &return_link($r);
 	}
 	return;
     }
-    my %slot=&Apache::lonnet::get_slot($env{'form.slotname'});
+
     my $reserved=&make_reservation($env{'form.slotname'},
 				   \%slot,$symb);
     my $description=&get_description($env{'form.slotname'},\%slot);
     if (defined($reserved)) {
-	if ($reserved > -1) {
+	if ($slot_name =~ /^error: (.*)/) {
+	    $r->print("<p>An error occured while attempting to make a reservation. ($1)</p>");
+	} elsif ($reserved > -1) {
 	    $r->print("<p>Success: $description</p>");
-	    $r->print('<p><a href="/adm/flip?postdata=return:">'.
-		      &mt('Return to last resource').'</a></p>');
-	    return;
 	} elsif ($reserved < 0) {
 	    $r->print("<p>Already reserved: $description</p>");
-	    $r->print('<p><a href="/adm/flip?postdata=return:">'.
-		      &mt('Return to last resource').'</a></p>');
-	    return;
 	}
+	&return_link($r);
+	return;
     }
 
     my %lt=('request'=>"Availibility list",
@@ -352,13 +491,13 @@ or
 </p>
 or
 STUFF
-    $r->print('<p><a href="/adm/flip?postdata=return:">'.
-	      &mt('Return to last resource').'</a></p>');
+
+    &return_link($r);
     return;
 }
 
 sub allowed_slot {
-    my ($slot_name,$slot,$symb)=@_;
+    my ($slot_name,$slot,$symb,$slots)=@_;
     #already started
     if ($slot->{'starttime'} < time) {
 	# all open slot to be schedulable
@@ -381,6 +520,12 @@ sub allowed_slot {
 	&& $slot->{'symb'} ne $symb) {
 	return 0;
     }
+    my $conflict = &check_for_conflict($symb,$slot_name,$slot,$slots);
+    if ($conflict) {
+	if ($slots->{$conflict}{'starttime'} < time) {
+	    return 0;
+	}
+    }
     &Apache::lonxml::debug("$slot_name symb good");
     return 1;
 }
@@ -404,26 +549,33 @@ sub show_choices {
     my $available;
     $r->print('<table border="1">');
     &Apache::lonxml::debug("Checking Slots");
-    my ($got_slot)=&check_for_reservation($symb);
+    my @got_slots=&check_for_reservation($symb,'allslots');
     foreach my $slot (sort 
 		      { return $slots{$a}->{'starttime'} <=> $slots{$b}->{'starttime'} }
 		      (keys(%slots)))  {
 
 	&Apache::lonxml::debug("Checking Slot $slot");
-	next if (!&allowed_slot($slot,$slots{$slot}));
+	next if (!&allowed_slot($slot,$slots{$slot},undef,\%slots));
 
 	$available++;
 
 	my $description=&get_description($slot,$slots{$slot});
 
 	my $form=&mt('Unavailable');
-	if (($slot eq $got_slot) ||
+	if ((grep(/^\Q$slot\E$/,@got_slots)) ||
 	    &space_available($slot,$slots{$slot},$symb)) {
 	    my $text=&mt('Select');
 	    my $command='get';
-	    if ($slot eq $got_slot) {
+	    if (grep(/^\Q$slot\E$/,@got_slots)) {
 		$text=&mt('Free Reservation');
 		$command='release';
+	    } else {
+		my $conflict = &check_for_conflict($symb,$slot,$slots{$slot},
+						   \%slots);
+		if ($conflict) {
+		    $text=&mt('Change Reservation');
+		    $command='get';
+		}
 	    }
 	    my $escsymb=&Apache::lonnet::escape($symb);
 	    $form=<<STUFF;
@@ -451,10 +603,15 @@ STUFF
 }
 
 sub to_show {
-    my ($when,$slot) = @_;
+    my ($slot,$when,$deleted) = @_;
     my $time=time;
     my $week=60*60*24*7;
-    if ($when eq 'now') {
+    if ($deleted eq 'hide' && $slot->{'type'} eq 'deleted') {
+	return 0;
+    }
+    if ($when eq 'any') {
+	return 1;
+    } elsif ($when eq 'now') {
 	if ($time > $slot->{'starttime'} &&
 	    $time < $slot->{'endtime'}) {
 	    return 1;
@@ -493,6 +650,24 @@ sub to_show {
     return 1;
 }
 
+sub remove_link {
+    my ($slotname,$entry,$uname,$udom,$symb) = @_;
+
+    $slotname  = &Apache::lonnet::escape($slotname);
+    $entry     = &Apache::lonnet::escape($entry);
+    $uname     = &Apache::lonnet::escape($uname);
+    $udom      = &Apache::lonnet::escape($udom);
+    $symb      = &Apache::lonnet::escape($symb);
+
+    my $remove= &mt('Remove');
+
+    return <<"END_LINK";
+ <a href="/adm/slotrequest?command=remove_registration&slotname=$slotname&entry=$entry&uname=$uname&udom=$udom&symb=$symb"
+   >($remove)</a>
+END_LINK
+
+}
+
 sub show_table {
     my ($r,$mgr)=@_;
 
@@ -514,10 +689,11 @@ sub show_table {
 	$r->print('</div>');
     }
     
-    my %Saveable_Parameters = ('show'  => 'array',
-			       'when'  => 'scalar',
-			       'order' => 'scalar');
-
+    my %Saveable_Parameters = ('show'    => 'array',
+			       'when'    => 'scalar',
+			       'order'   => 'scalar',
+			       'deleted' => 'scalar',
+			       );
     &Apache::loncommon::store_course_settings('slotrequest',\%Saveable_Parameters);
     &Apache::loncommon::restore_course_settings('slotrequest',\%Saveable_Parameters);
 
@@ -529,7 +705,7 @@ sub show_table {
 	     'endtime'      => 'End Time',
              'startreserve' => 'Time students can start reserving',
 	     'secret'       => 'Secret Word',
-	     'maxspace'     => 'Maxium # of students',
+	     'maxspace'     => 'Maximum # of students',
 	     'ip'           => 'IP or DNS restrictions',
 	     'symb'         => 'Resource slot is restricted to.',
 	     'uniqueperiod' => 'Period of time slot is unique',
@@ -543,22 +719,48 @@ sub show_table {
     my %show =  map { $_ => 1 } (@show);
 
     my %when_fields=&Apache::lonlocal::texthash(
-	     'now' => 'Open now',
+	     'now'      => 'Open now',
 	     'nextweek' => 'Open within the next week',
 	     'lastweek' => 'Were open last week',
 	     'willopen' => 'Will open later',
-	     'wereopen' => 'Were open');
-    my @when_order=('now','nextweek','lastweek','willopen','wereopen');
+	     'wereopen' => 'Were open',
+	     'any'      => 'Anytime',
+						);
+    my @when_order=('any','now','nextweek','lastweek','willopen','wereopen');
     $when_fields{'select_form_order'} = \@when_order;
     my $when = 	(exists($env{'form.when'})) ? $env{'form.when'}
                                             : 'now';
 
+    my $hide_radio = 
+	&Apache::lonhtmlcommon::radio('deleted',$env{'form.deleted'},'hide');
+    my $show_radio = 
+	&Apache::lonhtmlcommon::radio('deleted',$env{'form.deleted'},'show');
+	
     $r->print('<form method="POST" action="/adm/slotrequest">
 <input type="hidden" name="command" value="showslots" />');
     $r->print('<div>');
-    $r->print('<table class="inline"><tr><th>'.&mt('Show').'</th><th>'.&mt('Open').'</th></tr><tr><td>'.&Apache::loncommon::multiple_select_form('show',\@show,6,\%show_fields,\@show_order).
-	      '</td><td>'.&Apache::loncommon::select_form($when,'when',%when_fields).
-	      '</td></tr></table>');
+    $r->print('<table class="inline">
+      <tr><th>'.&mt('Show').'</th>
+          <th>'.&mt('Open').'</th>
+          <th>'.&mt('Options').'</th>
+      </tr>
+      <tr><td>'.&Apache::loncommon::multiple_select_form('show',\@show,6,\%show_fields,\@show_order).
+	      '</td>
+           <td>'.&Apache::loncommon::select_form($when,'when',%when_fields).
+          '</td>
+           <td>
+            <table>
+              <tr>
+                <td rowspan="2">Deleted slots:</td>
+                <td><label>'.$show_radio.'Show</label></td>
+              </tr>
+              <tr>
+                <td><label>'.$hide_radio.'Hide</label></td>
+              </tr>
+            </table>
+	  </td>
+       </tr>
+    </table>');
     $r->print('</div>');
     $r->print('<p><input type="submit" name="start" value="'.&mt('Update Display').'" /></p>');
     my $linkstart='<a href="/adm/slotrequest?command=showslots&amp;order=';
@@ -600,7 +802,7 @@ sub show_table {
 	return $slots{$a}->{'starttime'} <=> $slots{$b}->{'starttime'};
     };
     foreach my $slot (sort $slotsort (keys(%slots)))  {
-	if (!&to_show($when,$slots{$slot})) { next; }
+	if (!&to_show($slots{$slot},$when,$env{'form.deleted'})) { next; }
 	if (defined($slots{$slot}->{'type'})
 	    && $slots{$slot}->{'type'} ne 'schedulable_student') {
 	    #next;
@@ -609,10 +811,19 @@ sub show_table {
 	my %consumed=&Apache::lonnet::dump('slot_reservations',$cdom,$cnum,
 					   "^$slot\0");
 	my $ids;
-	foreach my $entry (sort(keys(%consumed))) {
-	    my (undef,$id)=split("\0",$entry);
-	    $ids.= $id.'-> '.$consumed{$entry}->{'name'}.'<br />';
+
+	my ($tmp)=%consumed;
+	if ($tmp !~ /^error: /) {
+	    foreach my $entry (sort(keys(%consumed))) {
+		my (undef,$id)=split("\0",$entry);
+		my ($uname,$udom) = split('@',$consumed{$entry}{'name'});
+		my $name = &Apache::loncommon::plainname($uname,$udom);
+		$ids.= '<nobr>'.$name.&remove_link($slot,$entry,$uname,$udom,
+						   $consumed{$entry}{'symb'})
+		    .'</nobr><br />';
+	    }
 	}
+
 	my $start=($slots{$slot}->{'starttime'}?
 		   &Apache::lonlocal::locallocaltime($slots{$slot}->{'starttime'}):'');
 	my $end=($slots{$slot}->{'endtime'}?
@@ -625,6 +836,7 @@ sub show_table {
 	    $unique=localtime($slots{$slot}{'uniqueperiod'}[0]).','.
 		localtime($slots{$slot}{'uniqueperiod'}[1]);
 	}
+
 	my $title;
 	if (exists($slots{$slot}{'symb'})) {
 	    my (undef,undef,$res)=
@@ -633,6 +845,7 @@ sub show_table {
 	    $title = &Apache::lonnet::gettitle($slots{$slot}{'symb'});
 	    $title='<a href="'.$res.'?symb='.$slots{$slot}{'symb'}.'">'.$title.'</a>';
 	}
+
 	my @proctors;
 	my $rowspan=1;
 	my $colspan=1;
@@ -652,23 +865,25 @@ sub show_table {
 	}
 	my $proctors=join(', ',@proctors);
 
-	my $edit=(<<EDITFORM);
-<form method="POST" action="/adm/helper/newslot.helper">
-  <input type="hidden" name="name" value="$slot" />
-  <input type="submit" name="Edit" value="Edit" />
-</form>
-EDITFORM
- 
-        $r->print("<tr>\n<td rowspan=\"$rowspan\">$edit</td>\n");
+	my $edit=(<<"EDITLINK");
+<a href="/adm/helper/newslot.helper?name=$slot">Edit</a>
+EDITLINK
+
+	my $delete=(<<"DELETELINK");
+<a href="/adm/slotrequest?command=delete&slotname=$slot">Delete</a>
+DELETELINK
+        if ($ids ne '') { undef($delete); }
+
+        $r->print("<tr>\n<td rowspan=\"$rowspan\">$edit $delete</td>\n");
 	if (exists($show{'name'})) {
 	    $colspan++;$r->print("<td>$slot</td>");
 	}
-	if (exists($show{'type'})) {
-	    $colspan++;$r->print("<td>$slots{$slot}->{'type'}</td>\n");
-	}
 	if (exists($show{'description'})) {
 	    $colspan++;$r->print("<td>$description</td>\n");
 	}
+	if (exists($show{'type'})) {
+	    $colspan++;$r->print("<td>$slots{$slot}->{'type'}</td>\n");
+	}
 	if (exists($show{'starttime'})) {
 	    $colspan++;$r->print("<td>$start</td>\n");
 	}
@@ -887,16 +1102,34 @@ sub csv_upload_assign {
     my $cname=$env{'course.'.$env{'request.course.id'}.'.num'};
     my $cdom=$env{'course.'.$env{'request.course.id'}.'.domain'};
     my $countdone=0;
+    my @errors;
     foreach my $slot (@slotdata) {
 	my %slot;
 	my %entries=&Apache::loncommon::record_sep($slot);
 	my $domain;
 	my $name=$entries{$fields{'name'}};
+	if ($name=~/^\s*$/) {
+	    push(@errors,"Did not create slot with no name");
+	    next;
+	}
+	if ($name=~/\s/) { 
+	    push(@errors,"$name not created -- Name must not contain spaces");
+	    next;
+	}
+	if ($name=~/\W/) { 
+	    push(@errors,"$name not created -- Name must contain only letters, numbers and _");
+	    next;
+	}
 	if ($entries{$fields{'type'}}) {
 	    $slot{'type'}=$entries{$fields{'type'}};
 	} else {
 	    $slot{'type'}='preassigned';
 	}
+	if ($slot{'type'} ne 'preassigned' &&
+	    $slot{'type'} ne 'schedulable_student') {
+	    push(@errors,"$name not created -- invalid type ($slot{'type'}) must be either preassigned or schedulable_student");
+	    next;
+	}
 	if ($entries{$fields{'starttime'}}) {
 	    $slot{'starttime'}=&UnixDate($entries{$fields{'starttime'}},"%s");
 	}
@@ -925,8 +1158,10 @@ sub csv_upload_assign {
 	$r->rflush();
 	$countdone++;
     }
-    $r->print("<br />Created $countdone slots\n");
-    $r->print("<br />\n");
+    $r->print("<p>Created $countdone slots\n</p>");
+    foreach my $error (@errors) {
+	$r->print("<p>$error\n</p>");
+    }
     &show_table($r,$mgr);
     return '';
 }
@@ -953,6 +1188,12 @@ sub handler {
 
     if ($env{'form.command'} eq 'showslots' && $vgr eq 'F') {
 	&show_table($r,$mgr);
+    } elsif ($env{'form.command'} eq 'remove_registration' && $mgr eq 'F') {
+	&remove_registration($r);
+    } elsif ($env{'form.command'} eq 'release' && $mgr eq 'F') {
+	&release_slot($r,undef,undef,undef,$mgr);
+    } elsif ($env{'form.command'} eq 'delete' && $mgr eq 'F') {
+	&delete_slot($r);
     } elsif ($env{'form.command'} eq 'uploadstart' && $mgr eq 'F') {
 	&upload_start($r);
     } elsif ($env{'form.command'} eq 'csvuploadmap' && $mgr eq 'F') {
@@ -971,12 +1212,15 @@ sub handler {
     } else {
 	my $symb=&Apache::lonnet::unescape($env{'form.symb'});
 	my (undef,undef,$res)=&Apache::lonnet::decode_symb($symb);
-	if ($res !~ /\.task$/) {
+	my $useslots = &Apache::lonnet::EXT("resource.0.useslots",$symb);
+	if ($useslots ne 'resource') {
 	    &fail($r,'not_valid');
 	    return OK;
 	}
 	$env{'request.symb'}=$symb;
-	my ($status) = &Apache::lonhomework::check_task_access('0');
+	my $type = ($res =~ /\.task$/) ? 'Task'
+	                               : 'problem';
+	my ($status) = &Apache::lonhomework::check_slot_access('0',$type);
 	if ($status eq 'CAN_ANSWER' ||
 	    $status eq 'NEEDS_CHECKIN' ||
 	    $status eq 'WAITING_FOR_GRADE') {
@@ -990,8 +1234,9 @@ sub handler {
 	} elsif ($env{'form.command'} eq 'get') {
 	    &get_slot($r,$symb);
 	} elsif ($env{'form.command'} eq 'change') {
-	    &release_slot($r,$symb,$env{'form.releaseslot'},1);
-	    &get_slot($r,$symb);
+	    if (&release_slot($r,$symb,$env{'form.releaseslot'},1)) {
+		&get_slot($r,$symb);
+	    }
 	} else {
 	    $r->print("<p>Unknown command: ".$env{'form.command'}."</p>");
 	}