--- loncom/interface/slotrequest.pm	2010/10/31 15:32:10	1.109
+++ loncom/interface/slotrequest.pm	2016/08/08 21:18:31	1.125.2.2
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Handler for requesting to have slots added to a students record
 #
-# $Id: slotrequest.pm,v 1.109 2010/10/31 15:32:10 raeburn Exp $
+# $Id: slotrequest.pm,v 1.125.2.2 2016/08/08 21:18:31 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -37,7 +37,7 @@ use Apache::lonnet;
 use Apache::lonnavmaps();
 use Date::Manip;
 use lib '/home/httpd/lib/perl/';
-use LONCAPA;
+use LONCAPA qw(:DEFAULT :match);
 
 sub fail {
     my ($r,$code)=@_;
@@ -56,12 +56,22 @@ sub fail {
 }
 
 sub start_page {
-    my ($r,$title,$brcrum)=@_;
+    my ($r,$title,$brcrum,$js)=@_;
     my $args;
     if (ref($brcrum) eq 'ARRAY') {
         $args = {bread_crumbs => $brcrum};
     }
-    $r->print(&Apache::loncommon::start_page($title,undef,$args));
+    if (($env{'form.requestattempt'}) || ($env{'form.command'} eq 'manageresv')) {
+        my %loaditems = (
+                           onload => 'javascript:uncheckSlotRadio();',
+                        );
+        if (ref($args) eq 'HASH') {
+            $args->{'add_entries'} = \%loaditems;
+        } else {
+            $args = { 'add_entries' => \%loaditems };
+        }
+    }
+    $r->print(&Apache::loncommon::start_page($title,$js,$args));
 }
 
 sub end_page {
@@ -69,6 +79,194 @@ sub end_page {
     $r->print(&Apache::loncommon::end_page());
 }
 
+sub reservation_js {
+    my ($slots,$consumed_uniqueperiods,$available,$got_slots,$symb) = @_;
+    return unless ((ref($slots) eq 'HASH') && (ref($available) eq 'ARRAY'));
+    my $toskip;
+    if ($symb eq '') {
+        $toskip = { symb => 1, };
+    }
+    my ($i,$j) = (0,0);
+    my $js;
+    foreach my $slot (sort
+        { return $slots->{$a}->{'starttime'} <=> $slots->{$b}->{'starttime'} }
+                    (keys(%{$slots})))  {
+
+        next if (!&allowed_slot($slot,$slots->{$slot},$symb,$slots,
+                                $consumed_uniqueperiods,$toskip));
+        $js .= "    slotstart[$i]='$slots->{$slot}->{'starttime'}';\n".
+               "    slotend[$i]='$slots->{$slot}->{'endtime'}';\n".
+               "    slotname[$i]='$slot';\n";
+        if (($symb) && (ref($got_slots) eq 'ARRAY')) {
+            if (grep(/^\Q$slot\E$/,@{$got_slots})) {
+                $js .= "    currslot[$j]='$slot';\n";
+                $j++;
+            }
+        }
+        $i++;
+        push(@{$available},$slot);
+    }
+    if ($j) {
+        $js = "    var currslot = new Array($j);\n\n$js";
+    }
+    my %alerts = &Apache::lonlocal::texthash (
+                                                none    => 'No reservable time slots found',
+                                                invalid => 'Invalid date format',
+                                             );
+    return <<"ENDSCRIPT";
+<script type="text/javascript">
+// <![CDATA[
+function updateSlotDisplay(form,num,slotpickradio) {
+    var slotstart = new Array($i);
+    var slotend = new Array($i);
+    var slotname = new Array($i);
+$js
+
+    if (slotpickradio == 'all') {
+        for (var i=0; i<$i; i++) {
+            if (document.getElementById('LC_slotrow_'+num+'_'+slotname[i])) {
+                document.getElementById('LC_slotrow_'+num+'_'+slotname[i]).style.display = '';
+            }
+            if (document.getElementById('LC_slotsearch_'+num)) {
+                document.getElementById('LC_slotsearch_'+num).style.display = 'block';
+            }
+        }
+    } else {
+        if (slotpickradio == 'show') {
+            for (var i=0; i<$i; i++) {
+                if (document.getElementById('LC_slotrow_'+num+'_'+slotname[i])) {
+                    document.getElementById('LC_slotrow_'+num+'_'+slotname[i]).style.display = 'none';
+                }
+            }
+            for (var j=0; j<$j; j++) {
+                if (document.getElementById('LC_slotrow_'+num+'_'+currslot[j])) {
+                    document.getElementById('LC_slotrow_'+num+'_'+currslot[j]).style.display = '';
+                }
+            }
+            if (document.getElementById('LC_slotsearch_'+num)) {
+                document.getElementById('LC_slotsearch_'+num).style.display = 'block';
+            }
+        } else {
+            var numberRegExp = /^[0-9]+\$/;
+            var startm = form.start_month.options[form.start_month.selectedIndex].value;
+            var startd = form.start_day.value;
+            startd=startd.trim();
+            var starty = form.start_year.value;
+            starty=starty.trim();
+            var endm = form.end_month.options[form.end_month.selectedIndex].value;
+            var endd = form.end_day.value;
+            endd=endd.trim();
+            var endy = form.end_year.value;
+            endy=endy.trim();
+            if (numberRegExp.test(endd) && numberRegExp.test(endy) && numberRegExp.test(startd) && numberRegExp.test(starty)) {
+                var startdate = startm+"/"+startd+"/"+starty;
+                var starttime = new Date(startdate).getTime();
+                starttime = starttime/1000;
+                var starth = form.start_hour.options[form.start_hour.selectedIndex].value;
+                if (numberRegExp.test(starth)) {
+                    starth = parseInt(starth);
+                    if (starth > 0 && starth <= 23) {
+                        starttime += 3600 * starth;
+                    }
+                }
+                var enddate = endm+"/"+endd+"/"+endy;
+                var endtime = new Date(enddate).getTime();
+                endtime = endtime/1000;
+                var endh = form.end_hour.options[form.end_hour.selectedIndex].value;
+                if (numberRegExp.test(endh)) {
+                    endh = parseInt(endh);
+                    if (endh > 0 && endh <= 23) {
+                        endtime += 3600 * endh;
+                    }
+                }
+
+                var shown = 0;
+                for (var i=0; i<$i; i++) {
+                    if ((slotstart[i] >= starttime) && (slotend[i] <= endtime)) {
+                        if (document.getElementById('LC_slotrow_'+num+'_'+slotname[i])) {
+                            document.getElementById('LC_slotrow_'+num+'_'+slotname[i]).style.display = '';
+                            shown ++;
+                        }
+                    } else {
+                        if (document.getElementById('LC_slotrow_'+num+'_'+slotname[i])) {
+                            document.getElementById('LC_slotrow_'+num+'_'+slotname[i]).style.display = 'none';
+                        }
+                    }
+                }
+                if (document.getElementById('LC_slotsearch_'+num)) {
+                    if (shown) {
+                        document.getElementById('LC_slotsearch_'+num).style.display = 'block';
+                    } else {
+                        document.getElementById('LC_slotsearch_'+num).style.display = 'none';
+                    }
+                }
+                if (shown == 0) {
+                    alert('$alerts{"none"}');
+                }
+            } else {
+                alert('$alerts{"invalid"}');
+            }
+        }
+    }
+    return;
+}
+
+function toggleSlotDisplay(form,num) {
+    if (form.slotpick.length) {
+        for (var i=0; i<form.slotpick.length; i++) {
+            if (form.slotpick[i].checked) {
+                var val = form.slotpick[i].value;
+                if (document.getElementById('LC_slotfilter_'+num)) {
+                    document.getElementById('LC_slotsearch_'+num).style.display = 'none';
+                    if (val == 'filter') {
+                        document.getElementById('LC_slotfilter_'+num).style.display = 'block';
+                    } else {
+                        document.getElementById('LC_slotfilter_'+num).style.display = 'none';
+                        if (val == 'all') {
+                            updateSlotDisplay(form,num,val);
+                        } else {
+                            updateSlotDisplay(form,num,val);
+                        }
+                    }
+                }
+                break;
+            }
+        }
+    }
+    return false;
+}
+
+if (!document.getElementsByClassName) {
+    function getElementsByClassName(node, classname) {
+        var a = [];
+        var re = new RegExp('(^| )'+classname+'( |$)');
+        var els = node.getElementsByTagName("*");
+        for(var i=0,j=els.length; i<j; i++)
+            if(re.test(els[i].className))a.push(els[i]);
+        return a;
+    }
+}
+
+function uncheckSlotRadio() {
+    var slotpicks;
+    if (document.getElementsByClassName) {
+        slotpicks = document.getElementsByClassName('LC_slotpick_radio');
+    } else {
+        slotpicks = getElementsByClassName(document.body,'LC_slotpick_radio');
+    }
+    if (slotpicks.length) {
+        for (var i=0; i<slotpicks.length; i++) {
+            slotpicks[i].checked = false;  
+        }
+    }
+}
+// ]]>
+</script>
+ENDSCRIPT
+
+}
+
+
 =pod
 
  slot_reservations db
@@ -121,7 +319,6 @@ sub check_for_reservation {
     my ($symb,$mode)=@_;
     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'}, $env{'user.name'});
     my @slots = (split(/:/,$student), split(/:/, $course));
@@ -137,16 +334,20 @@ sub check_for_reservation {
 	return 'error: Unable to determine current status';
     }    
     my @got;
-    my @sorted_slots = &Apache::loncommon::sorted_slots(\@slots,\%slots);
+    my @sorted_slots = &Apache::loncommon::sorted_slots(\@slots,\%slots,'starttime');
     foreach my $slot_name (@sorted_slots) {
 	next if (!defined($slots{$slot_name}) ||
 		 !ref($slots{$slot_name}));
 	&Apache::lonxml::debug(time." $slot_name ".
 			       $slots{$slot_name}->{'starttime'}." -- ".
-			       $slots{$slot_name}->{'startreserve'});
-	if ($slots{$slot_name}->{'endtime'} > time &&
-	    $slots{$slot_name}->{'startreserve'} < time) {
-	    # between start of reservation times and end of slot
+			       $slots{$slot_name}->{'startreserve'}." -- ".
+                               $slots{$slot_name}->{'endreserve'});
+	if (($slots{$slot_name}->{'endtime'} > time) &&
+	    ($slots{$slot_name}->{'startreserve'} < time) &&
+            ((!$slots{$slot_name}->{'endreserve'}) || 
+             ($slots{$slot_name}->{'endreserve'} > time))) {
+	    # between start of reservation time and end of reservation time
+            # and before end of slot
 	    if ($mode eq 'allslots') {
 		push(@got,$slot_name);
 	    } else {
@@ -214,16 +415,19 @@ sub check_for_conflict {
     if (!defined($new_slot->{'uniqueperiod'})) { return undef; }
 
     if (!ref($consumed_uniqueperiods)) {
-	$consumed_uniqueperiods = &get_consumed_uniqueperiods($slots);
-        if (ref($consumed_uniqueperiods) eq 'HASH') {
-	    if (&Apache::lonnet::error(%$consumed_uniqueperiods)) {
-	        return 'error: Unable to determine current status';
-	    }
+        if ($consumed_uniqueperiods =~ /^error: /) {
+            return $consumed_uniqueperiods;
         } else {
-            return 'error: Unable to determine current status';
+	    $consumed_uniqueperiods = &get_consumed_uniqueperiods($slots);
+            if (ref($consumed_uniqueperiods) eq 'HASH') {
+	        if (&Apache::lonnet::error(%$consumed_uniqueperiods)) {
+	            return 'error: Unable to determine current status';
+	        }
+            } else {
+                return 'error: Unable to determine current status';
+            }
         }
-    }
-    
+    } 
     my ($new_uniq_start,$new_uniq_end) = @{$new_slot->{'uniqueperiod'}};
     foreach my $slot_name (keys(%$consumed_uniqueperiods)) {
 	my ($start,$end)=@{$consumed_uniqueperiods->{$slot_name}};
@@ -335,12 +539,12 @@ sub store_slot_parm {
                        context => $env{'form.context'},
                     );
 
-    &Apache::lonnet::instructor_log('slotreservationslog',\%storehash,
-                                    '',$env{'user.name'},$env{'user.domain'},
-                                    $cnum,$cdom);
-    &Apache::lonnet::instructor_log($cdom.'_'.$cnum.'_slotlog',\%storehash,
-                                    1,$env{'user.name'},$env{'user.domain'},
-                                    $env{'user.name'},$env{'user.domain'});
+    &Apache::lonnet::write_log('course','slotreservationslog',\%storehash,
+                               '',$env{'user.name'},$env{'user.domain'},
+                               $cnum,$cdom);
+    &Apache::lonnet::write_log('course',$cdom.'_'.$cnum.'_slotlog',\%storehash,
+                               1,$env{'user.name'},$env{'user.domain'},
+                               $env{'user.name'},$env{'user.domain'});
 
     return;
 }
@@ -500,14 +704,20 @@ sub release_reservation {
         return (0,'error: Unable to determine current status');
     }
     my $passed_resource = $navmap->getBySymb($symb);
-    if ($passed_resource->is_map()) {
-	my ($a_resource) = 
-	    $navmap->retrieveResources($passed_resource, 
-				       sub {$_[0]->is_problem()},0,1);
-	$symb = $a_resource->symb();
+    if (ref($passed_resource)) {
+        if ($passed_resource->is_map()) {
+	    my ($a_resource) = 
+                $navmap->retrieveResources($passed_resource, 
+                                           sub {$_[0]->is_problem()},0,1);
+            $symb = $a_resource->symb();
+        }
+    } else {
+        unless ($mgr eq 'F') {
+            return (0,'error: Unable to determine current status');
+        }
     }
 
-    # get parameter string, check for existance, rebuild string with the slot
+    # get parameter string, check for existence, rebuild string with the slot
     my $student = &Apache::lonnet::EXT("resource.0.availablestudent",
                                        $symb,$udom,$uname);
     my @slots = split(/:/,$student);
@@ -534,10 +744,10 @@ sub release_reservation {
                                action  => 'release',
                                context => $env{'form.context'},
                         );
-            &Apache::lonnet::instructor_log('slotreservationslog',\%storehash,
-                                            1,$uname,$udom,$cnum,$cdom);
-            &Apache::lonnet::instructor_log($cdom.'_'.$cnum.'_slotlog',\%storehash,
-                                            1,$uname,$udom,$uname,$udom);
+            &Apache::lonnet::write_log('slotreservationslog',\%storehash,
+                                       1,$uname,$udom,$cnum,$cdom);
+            &Apache::lonnet::write_log($cdom.'_'.$cnum.'_slotlog',\%storehash,
+                                       1,$uname,$udom,$uname,$udom);
 	}
     }
 
@@ -641,16 +851,19 @@ sub get_slot {
    <input type="hidden" name="releaseslot" value="$slot_name" />
    <input type="hidden" name="command" value="change" />
 STUFF
-            $r->print('<p class="LC_error">'.&mt('Reservation currently unchanged').'</p>'.
-                      '<p class="LC_warning">');
+            $r->print('<p class="LC_error">'.&mt('Reservation currently unchanged').'</p>');
             if ($slot_name ne '') {
-                $r->print(&mt('To complete the transaction you [_1]must[_2] confirm you want the change to [_3] to be processed.'
-                         ,'<b>','</b>','<b>'.$description2.'</b>').'<br />'
-                         .'<input type="submit" name="change" value="'.&mt('Process change').'" /></p>' 
-                         .&mt('or').'<br /><p>'.&mt('you will continue with the reservation you already had: [_1]'
-                         ,'<b>'.$description1.'</b>').'</p>');
+                $r->print('<p>'.&mt('To complete the transaction you [_1]must confirm[_2] you want to [_3]process the change[_4] to [_5].'
+                         ,'<b>','</b>','<i>','</i>','<b>'.$description2.'</b>')
+                         .'<br />'
+                         .&mt('Or you can choose to [_1]make no change[_2] and continue[_2] with the reservation you already had: [_3].'
+                         ,'<i>','</i>','<b>'.$description1.'</b>')
+                         .'</p><p><span class="LC_nobreak">'
+                         .'<input type="submit" name="change" value="'.&mt('Process the change').'" />' 
+                         .('&nbsp;'x3)
+                         .'<input type="submit" name="nochange" value="'.&mt('Make no change').'" />'
+                         .'</span></p>');
             }
-	    &return_link($r);
 	    $r->print(<<STUFF);
 </form>
 STUFF
@@ -689,7 +902,7 @@ STUFF
     }
 
     my %lt = &Apache::lonlocal::texthash(
-        'request' => 'Availibility list',
+        'request' => 'Availability list',
         'try'     => 'Try again?',
         'or'      => 'or',
     );
@@ -728,7 +941,7 @@ STUFF
 }
 
 sub allowed_slot {
-    my ($slot_name,$slot,$symb,$slots,$consumed_uniqueperiods)=@_;
+    my ($slot_name,$slot,$symb,$slots,$consumed_uniqueperiods,$toskip)=@_;
 
     #already started
     if ($slot->{'starttime'} < time) {
@@ -753,6 +966,11 @@ sub allowed_slot {
     if ($slot->{'startreserve'} > time) {
 	return 0;
     }
+    # reserve time ended
+    if (($slot->{'endreserve'}) &&
+        ($slot->{'endreserve'} < time)) {
+        return 0;
+    }    
     &Apache::lonxml::debug("$slot_name reserve good");
 
     my $userallowed=0;
@@ -799,7 +1017,9 @@ sub allowed_slot {
     # not allowed for this resource
     if (defined($slot->{'symb'})
 	&& $slot->{'symb'} ne $symb) {
-	return 0;
+        unless ((ref($toskip) eq 'HASH') && ($toskip->{'symb'})) {
+	    return 0;
+        }
     }
 
     my $conflict = &check_for_conflict($symb,$slot_name,$slot,$slots,
@@ -827,45 +1047,14 @@ sub get_description {
 }
 
 sub show_choices {
-    my ($r,$symb,$formname)=@_;
-
-    my ($cnum,$cdom)=&get_course();
-    my %slots=&Apache::lonnet::dump('slots',$cdom,$cnum);
-    my $consumed_uniqueperiods = &get_consumed_uniqueperiods(\%slots);
-    if (ref($consumed_uniqueperiods) eq 'HASH') {
-        if (&Apache::lonnet::error(%$consumed_uniqueperiods)) {
-            $r->print('<span class="LC_error">'.
-                      &mt('An error occurred determining slot availability').
-                      '</span>');
-            return;
-        }
-    } elsif ($consumed_uniqueperiods =~ /^error: /) {
-        $r->print('<span class="LC_error">'.
-                  &mt('An error occurred determining slot availability').
-                  '</span>');
-        return;
-    }
-    my (@available,$output);
+    my ($r,$symb,$formname,$num,$slots,$consumed_uniqueperiods,$available,$got_slots)=@_;
+    my $output;
     &Apache::lonxml::debug("Checking Slots");
-    my @got_slots=&check_for_reservation($symb,'allslots');
-    if ($got_slots[0] =~ /^error: /) {
-        $r->print('<span class="LC_error">'.
-                  &mt('An error occurred determining slot availability').
-                  '</span>');
+    if (!ref($available) eq 'ARRAY') {
         return;
     }
-    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},$symb,\%slots,
-				$consumed_uniqueperiods));
-
-        push(@available,$slot);
-    }
-    if (!@available) {
-        $output = &mt('No available times.');
+    if (!@{$available}) {
+        $output = '<span class="LC_info">'.&mt('No available times.').'</span>';
         if ($env{'form.command'} ne 'manageresv') {
             $output .= ' <a href="/adm/flip?postdata=return:">'.
                        &mt('Return to last resource').'</a>';
@@ -873,30 +1062,101 @@ sub show_choices {
         $r->print($output);
         return;
     }
+    if (@{$available} > 1) {
+        my $numavailable = scalar(@{$available});
+        my $numreserved = 0;
+        my $js;
+        my $j = 0;
+        foreach my $got (@{$got_slots}) {
+            unless (($got eq '') || (!defined($got))) {
+                $numreserved ++;
+                if ($env{'form.command'} eq 'manageresv') {
+                    $js .= "    currslot[$j]='$got';\n";
+                    $j++;
+                }
+            }
+        }
+        my $showfilter = 'none';
+        $output .= '<fieldset><legend>'.&mt('Actions').'</legend>'."\n".
+                   '<form method="post" name="reservationdisplay_'.$num.
+                   '" action="" onsubmit="toggleSlotDisplay(this.form,'."'$num'".');">';
+        my @options = ('all','filter');
+        if ($numreserved) {
+            unshift(@options,'show');
+        }
+        my %resmenu = &Apache::lonlocal::texthash (
+                                         show   => 'Show current reservation',
+                                         all    => 'Show all', 
+                                         filter => 'Search by date',
+                     );
+        foreach my $option (@options) {
+            my $onclick = "toggleSlotDisplay(this.form,'$num');";
+            if (($option eq 'show') && ($env{'form.command'} eq 'manageresv')) {  
+                $onclick .= "currSlotDisplay$num(this.form,'$num');"; 
+            }
+            $output .= '<span class="LC_nobreak"><label>'.
+                       '<input type="radio" class="LC_slotpick_radio" name="slotpick" value="'.
+                       $option.'" onclick="'.$onclick.'" />'.
+                       $resmenu{$option}.
+                       '</label></span>'.('&nbsp;' x3)."\n";
+        }
+        $output .= '</form>';
+        my $chooserform = 'reservationchooser_'.$num;
+        my $starttime = $slots->{$available->[0]}->{'starttime'};
+        my $endtime = $slots->{$available->[-1]}->{'starttime'};
+        if ($env{'form.command'} eq 'manageresv') {
+            $output .= <<"ENDSCRIPT";
+
+<script type="text/javascript">
+// <![CDATA[
+function currSlotDisplay$num() {
+    var currslot = new Array($numreserved);
+$js    
+    for (var j=0; j<$numreserved; j++) {
+        if (document.getElementById('LC_slotrow_$num\_'+currslot[j])) {
+            document.getElementById('LC_slotrow_$num\_'+currslot[j]).style.display = '';
+        }
+    }
+}
+// ]]>
+</script>
+
+ENDSCRIPT
+        }
+        $output .=
+            '<div id="LC_slotfilter_'.$num.'" style="display:'.$showfilter.'">'.
+            '<form method="post" name="'.$chooserform.'" action="">'.
+            '<table><tr><td>'.&mt('Open after').'</td><td>'.
+            &Apache::lonhtmlcommon::date_setter($chooserform,'start',$starttime,'','','','','','','',1,1).
+            '</td></tr><tr><td>'.&mt('Closed before').'</td><td>'.
+            &Apache::lonhtmlcommon::date_setter($chooserform,'end',$endtime,'','','','','','','',1,1).
+            '</td></tr></table><br />'.
+            '<input type="button" name="slotfilter" value="Search for reservable slots" onclick="updateSlotDisplay(this.form,'."'$num'".');" />'.
+            '</form></div><div id="LC_slotsearch_'.$num.'" style="display:none"><hr />';
+    }
     if ($env{'form.command'} eq 'manageresv') {
-        $output = '<table border="0">';
+        $output .= '<table border="0">';
     } else {
-        $output = &Apache::loncommon::start_data_table();
+        $output .= &Apache::loncommon::start_data_table();
     }
-    foreach my $slot (@available) { 
-	my $description=&get_description($slot,$slots{$slot});
+    foreach my $slot (@{$available}) {
+	my $description=&get_description($slot,$slots->{$slot});
 	my $form;
-	if ((grep(/^\Q$slot\E$/,@got_slots)) ||
-	    &space_available($slot,$slots{$slot},$symb)) {
+	if ((grep(/^\Q$slot\E$/,@{$got_slots})) ||
+	    &space_available($slot,$slots->{$slot},$symb)) {
 	    my $text=&mt('Select');
 	    my $command='get';
-	    if (grep(/^\Q$slot\E$/,@got_slots)) {
+	    if (grep(/^\Q$slot\E$/,@{$got_slots})) {
 		$text=&mt('Drop Reservation');
 		$command='release';
 	    } else {
-		my $conflict = &check_for_conflict($symb,$slot,$slots{$slot},
-						   \%slots,
-						   $consumed_uniqueperiods);
+		my $conflict = &check_for_conflict($symb,$slot,$slots->{$slot},
+						   $slots,$consumed_uniqueperiods);
                 if ($conflict) {
                     if ($conflict =~ /^error: /) {
                         $form = '<span class="LC_error">'.
-                                &mt('Slot: [_1] has unknown status.',$description).
-                                '</span>';
+                                 &mt('Slot: [_1] has unknown status.',$description).
+                                 '</span>';
                     } else {
 		        $text=&mt('Change Reservation');
 		        $command='get';
@@ -905,15 +1165,16 @@ sub show_choices {
 	    }
 	    my $escsymb=&escape($symb);
             if (!$form) {
+                my $name;
                 if ($formname) {
-                    $formname = 'name="'.$formname.'" ';
+                     $name = 'name="'.$formname.'"';
                 }
                 my $context = 'user';
                 if ($env{'form.command'} eq 'manageresv') {
                     $context = 'usermanage';
                 }
 	        $form=<<STUFF;
-   <form method="post" action="/adm/slotrequest" $formname>
+   <form method="post" action="/adm/slotrequest" $name>
      <input type="submit" name="Select" value="$text" />
      <input type="hidden" name="symb" value="$escsymb" />
      <input type="hidden" name="slotname" value="$slot" />
@@ -926,9 +1187,9 @@ STUFF
             $form = &mt('Unavailable');
         }
         if ($env{'form.command'} eq 'manageresv') {
-            $output .= '<tr>';
+            $output .= '<tr id="LC_slotrow_'.$num.'_'.$slot.'" >';
         } else {
-	    $output .= &Apache::loncommon::start_data_table_row();
+	    $output .= &Apache::loncommon::start_data_table_row('','LC_slotrow_'.$num.'_'.$slot);
         }
         $output .= " 
  <td>$form</td>
@@ -942,9 +1203,13 @@ STUFF
     if ($env{'form.command'} eq 'manageresv') {
         $output .= '</table>';
     } else {
-       $output .= &Apache::loncommon::end_data_table();
+        $output .= &Apache::loncommon::end_data_table();
+    }
+    if (@{$available} > 1) {
+        $output .= '</div></fieldset>';
     }
     $r->print($output);
+    return;
 }
 
 sub to_show {
@@ -1046,7 +1311,8 @@ sub show_table {
     my $available;
     if ($mgr eq 'F') {
     # FIXME: This line should be deleted once Slots uses breadcrumbs
-    $r->print(&Apache::loncommon::help_open_topic('Slot About', 'Help on slots'));
+    $r->print('<br />'.&Apache::loncommon::help_open_topic(
+        'Slot About', &mt('Help on slots')));
 
 	$r->print('<div>');
 	$r->print('<form method="post" action="/adm/slotrequest">
@@ -1062,11 +1328,11 @@ sub show_table {
     }
 
     if (!keys(%slots)) {
-        if ($crstype eq 'Community') {
-            $r->print('<div>'.&mt('No slots have been created in this community.').'</div>');
-        } else {
-            $r->print('<div>'.&mt('No slots have been created in this course.').'</div>');
-        }
+        $r->print(
+            '<p class="LC_info">'
+           .&mt('No slots have been created in this '.lc($crstype).'.')
+           .'</p>'
+        );
         return;
     }
     
@@ -1093,6 +1359,7 @@ sub show_table {
 	     'starttime'       => 'Start time',
 	     'endtime'         => 'End Time',
              'startreserve'    => 'Time students can start reserving',
+             'endreserve'      => 'Time students can no longer reserve',
              'reservationmsg'  => 'Message triggered by reservation',
 	     'secret'          => 'Secret Word',
 	     'space'           => '# of students/max',
@@ -1105,11 +1372,12 @@ sub show_table {
 	     'proctor'         => 'List of proctors');
     if ($crstype eq 'Community') {
         $show_fields{'startreserve'} = &mt('Time members can start reserving');
+        $show_fields{'endreserve'} = &mt('Time members can no longer reserve');
         $show_fields{'scheduled'} = &mt('Scheduled Members');
     }
     my @show_order=('name','description','type','starttime','endtime',
-		    'startreserve','reservationmsg','secret','space','ip','symb',
-		    'allowedsections','allowedusers','uniqueperiod',
+		    'startreserve','endreserve','reservationmsg','secret','space',
+		    'ip','symb','allowedsections','allowedusers','uniqueperiod',
 		    'scheduled','proctor');
     my @show = 
 	(exists($env{'form.show'})) ? &Apache::loncommon::get_env_multiple('form.show')
@@ -1195,11 +1463,11 @@ sub show_table {
            <td valign="top">
             <table>
               <tr>
-                <td rowspan="2">Deleted slots:</td>
-                <td><label>'.$show_radio.'Show</label></td>
+                <td rowspan="2">'.&mt('Deleted slots:').'</td>
+                <td><label>'.$show_radio.&mt('Show').'</label></td>
               </tr>
               <tr>
-                <td><label>'.$hide_radio.'Hide</label></td>
+                <td><label>'.$hide_radio.&mt('Hide').'</label></td>
               </tr>
             </table>
 	  </td>
@@ -1220,7 +1488,7 @@ sub show_table {
 
     my %name_cache;
     my $slotsort = sub {
-	if ($env{'form.order'}=~/^(type|description|endtime|startreserve|ip|symb|allowedsections|allowedusers|reservationmsg)$/) {
+	if ($env{'form.order'}=~/^(type|description|endtime|startreserve|endreserve|ip|symb|allowedsections|allowedusers|reservationmsg)$/) {
 	    if (lc($slots{$a}->{$env{'form.order'}})
 		ne lc($slots{$b}->{$env{'form.order'}})) {
 		return (lc($slots{$a}->{$env{'form.order'}}) 
@@ -1302,6 +1570,8 @@ sub show_table {
 		 &Apache::lonlocal::locallocaltime($slots{$slot}->{'endtime'}):'');
 	my $start_reserve=($slots{$slot}->{'startreserve'}?
 			   &Apache::lonlocal::locallocaltime($slots{$slot}->{'startreserve'}):'');
+        my $end_reserve=($slots{$slot}->{'endreserve'}?
+                         &Apache::lonlocal::locallocaltime($slots{$slot}->{'endreserve'}):'');
 	
 	my $unique;
 	if (ref($slots{$slot}{'uniqueperiod'})) {
@@ -1409,6 +1679,9 @@ LOGLINK
 	if (exists($show{'startreserve'})) {
 	    $colspan++;$r->print("<td>$start_reserve</td>\n");
 	}
+        if (exists($show{'endreserve'})) {
+            $colspan++;$r->print("<td>$end_reserve</td>\n");
+        }
         if (exists($show{'reservationmsg'})) {
             $colspan++;$r->print("<td>$reservemsg</td>\n");
         }
@@ -1457,7 +1730,7 @@ STUFF
 }
 
 sub manage_reservations {
-    my ($r,$crstype) = @_;
+    my ($r,$crstype,$slots,$consumed_uniqueperiods,$allavailable) = @_;
     my $navmap = Apache::lonnavmaps::navmap->new();
     $r->print('<p>'
              .&mt('Instructors may use a reservation system to place restrictions on when and where assignments can be worked on.')
@@ -1476,6 +1749,19 @@ sub manage_reservations {
         &Apache::lonnet::logthis('Manage Reservations - could not create navmap object in '.lc($crstype).':'.$env{'request.course.id'});
         return;
     }
+    if (ref($consumed_uniqueperiods) eq 'HASH') {
+        if (&Apache::lonnet::error(%$consumed_uniqueperiods)) {
+            $r->print('<span class="LC_error">'.
+                      &mt('An error occurred determining slot availability.').
+                      '</span>');
+            return;
+        }
+    } elsif ($consumed_uniqueperiods =~ /^error: /) {
+        $r->print('<span class="LC_error">'.
+                  &mt('An error occurred determining slot availability.').
+                  '</span>');
+        return;
+    }
     my (%parent,%shownparent,%container,%container_title,%contents);
     my ($depth,$count,$reservable,$lastcontainer,$rownum) = (0,0,0,0,0);
     my @backgrounds = ("LC_odd_row","LC_even_row");
@@ -1547,6 +1833,8 @@ sub manage_reservations {
                 } elsif ($slot_status == $resource->RESERVABLE) {
                     $msg=&mt('Reservation needed');
                     $get_choices = 1;
+                } elsif ($slot_status == $resource->RESERVABLE_LATER) {
+                    $msg=&mt('Reservation needed: will be reservable later.');
                 } elsif ($slot_status == $resource->NOTRESERVABLE) {
                     $msg=&mt('Reservation needed: none available.');
                 } elsif ($slot_status == $resource->UNKNOWN) {
@@ -1612,15 +1900,38 @@ sub manage_reservations {
                     }
                 }
                 if ($hasaction) {
-                    $result .= '<td valgn="middle">'.$msg.'</td>'.
-                               '<td valign="middle">'.('&nbsp;' x6);
+                    $result .= '<td valign="top">'.$msg.'</td>'.
+                               '<td valign="top">';
                 } else {
                     $result .= '<td colspan="2" valign="middle">'.$msg.'</td>';
                 }
                 $r->print($result);
                 if ($hasaction) {
-                    my $formname = 'manageres_'.$reservable;
-                    &show_choices($r,$symb,$formname);
+                    my @got_slots=&check_for_reservation($symb,'allslots');
+                    if ($got_slots[0] =~ /^error: /) {
+                        $r->print('<span class="LC_error">'.
+                                  &mt('An error occurred determining slot availability.').
+                                  '</span>');
+                    } else {
+                        my $formname = 'manageres_'.$reservable;
+                        if (ref($allavailable) eq 'ARRAY') {
+                            my @available;
+                            if (ref($slots) eq 'HASH') {
+                                foreach my $slot (@{$allavailable}) {
+                                # not allowed for this resource
+                                    if (ref($slots->{$slot}) eq 'HASH') {
+                                        if ((defined($slots->{$slot}->{'symb'})) && 
+                                            ($slots->{$slot}->{'symb'} ne $symb)) {
+                                            next;
+                                        }
+                                    }
+                                    push(@available,$slot);
+                                }
+                            }  
+                            &show_choices($r,$symb,$formname,$reservable,$slots,$consumed_uniqueperiods,
+                                          \@available,\@got_slots);
+                        }
+                    }
                     $r->print('</td>');
                 }
                 $r->print('</tr>');
@@ -1780,6 +2091,7 @@ sub show_reservations {
             $r->print('</tr></table>');
             $r->print(<<"ENDSCRIPT");
 <script type="text/javascript">
+// <![CDATA[
 function chgPage(caller) {
     if (caller == 'previous') {
         document.$formname.page.value --;
@@ -1790,6 +2102,7 @@ function chgPage(caller) {
     document.$formname.submit();
     return;
 }
+// ]]>
 </script>
 ENDSCRIPT
         }
@@ -2027,7 +2340,7 @@ sub get_resource_title {
                 $maptitle = $maptitles->{$mapurl};
             } else {
                 if ($mapurl eq $env{'course.'.$env{'request.course.id'}.'.url'}) {
-                    $maptitle=&mt('Main Course Documents');
+                    $maptitle=&mt('Main Content');
                 } else {
                     $maptitle=&Apache::lonnet::gettitle($mapurl);
                 }
@@ -2163,6 +2476,8 @@ sub slot_change_messaging {
             $msgtitle = &mt('Status of messages about saved reservation');
         } elsif ($action eq 'release') {
             $msgtitle = &mt('Status of messages about dropped reservation');
+        } elsif ($action eq 'nochange') {
+            $msgtitle = &mt('Status of messages about unchanged existing reservation');
         }
         return '<span class="LC_info">'.$msgtitle.'</span>'
                .'<ul>'
@@ -2176,7 +2491,7 @@ sub upload_start {
     my ($r)=@_;    
     $r->print(
         &Apache::grades::checkforfile_js()
-       .'<h3>'.&mt('Specify a file containing the slot definitions.').'</h3>'
+       .'<h2>'.&mt('Upload a file containing the slot definitions').'</h2>'
        .'<form method="post" enctype="multipart/form-data"'
        .' action="/adm/slotrequest" name="slotupload">'
        .'<input type="hidden" name="command" value="csvuploadmap" />'
@@ -2210,16 +2525,40 @@ sub csvuploadmap_header {
 
     my $checked=(($env{'form.noFirstLine'})?' checked="checked"':'');
     my $ignore=&mt('Ignore First Line');
-	my $help_field = &Apache::loncommon::help_open_topic('Slot SelectingField');
+    my $buttontext = &mt('Reverse Association');
+
+    $r->print(
+        '<form method="post" enctype="multipart/form-data" action="/adm/slotrequest" name="slotupload">'
+       .'<h2>'.&mt('Identify fields in uploaded list').'</h2>'
+       .'<div class="LC_columnSection">'
+       .&Apache::loncommon::help_open_topic(
+            'Slot About',&mt('Help on slots'))
+       .' '.&Apache::loncommon::help_open_topic(
+            'Slot SelectingField',&mt('Help on selecting Fields'))
+       ."</div>\n"
+       .'<p class="LC_info">'
+       .&mt('Total number of records found in file: [_1]','<b>'.$distotal.'</b>')
+       ."</p>\n"
+    );
+    if ($distotal == 0) {
+        $r->print('<p class="LC_warning">'.&mt('None found').'</p>');
+    }
+    $r->print(
+        '<p>'
+       .&mt('Enter as many fields as you can.').'<br />'
+       .&mt('The system will inform you and bring you back to this page,[_1]if the data selected is insufficient to create the slots.','<br />')
+       .'</p>'
+    );
+    $r->print(
+        '<div class="LC_left_float">'
+       .'<fieldset><legend>'.&mt('Functions').'</legend>'
+       .'<label><input type="checkbox" name="noFirstLine"'.$checked.' />'.$ignore.'</label>'
+       .' <input type="button" value="'.$buttontext
+           .'" onclick="javascript:this.form.associate.value=\'Reverse Association\';submit(this.form);" />'
+       .'</fieldset></div><br clear="all" />'
+    );
 
     $r->print(<<ENDPICK);
-<form method="post" enctype="multipart/form-data" action="/adm/slotrequest" name="slotupload">
-<h3>Identify fields $help_field</h3>	
-Total number of records found in file: $distotal <hr />
-Enter as many fields as you can. The system will inform you and bring you back
-to this page if the data selected is insufficient to create the slots.<hr />
-<input type="button" value="Reverse Association" onclick="javascript:this.form.associate.value='Reverse Association';submit(this.form);" />
-<label><input type="checkbox" name="noFirstLine"$checked />$ignore</label>
 <input type="hidden" name="associate"  value="" />
 <input type="hidden" name="datatoken"  value="$datatoken" />
 <input type="hidden" name="fileupload" value="$env{'form.fileupload'}" />
@@ -2227,9 +2566,10 @@ to this page if the data selected is ins
 <input type="hidden" name="upfile_associate" 
                                        value="$env{'form.upfile_associate'}" />
 <input type="hidden" name="command"    value="csvuploadassign" />
-<hr />
 <script type="text/javascript" language="Javascript">
+// <![CDATA[
 $javascript
+// ]]>
 </script>
 ENDPICK
     return '';
@@ -2240,7 +2580,6 @@ sub csvuploadmap_footer {
     my ($request,$i,$keyfields) =@_;
     my $buttontext = &mt('Create Slots');
     $request->print(<<ENDPICK);
-</table>
 <input type="hidden" name="nfields" value="$i" />
 <input type="hidden" name="keyfields" value="$keyfields" />
 <input type="button" onclick="javascript:verify(this.form)" value="$buttontext" /><br />
@@ -2249,7 +2588,7 @@ ENDPICK
 }
 
 sub csvupload_javascript_reverse_associate {
-    my $error1=&mt('You need to specify the name, starttime, endtime and a type');
+    my $error1=&mt('You need to specify the name, start time, end time and a type.');
     return(<<ENDPICK);
   function verify(vf) {
     var foundstart=0;
@@ -2275,7 +2614,7 @@ ENDPICK
 }
 
 sub csvupload_javascript_forward_associate {
-    my $error1=&mt('You need to specify the name, starttime, endtime and a type');
+    my $error1=&mt('You need to specify the name, start time, end time and a type.');
   return(<<ENDPICK);
   function verify(vf) {
     var foundstart=0;
@@ -2342,6 +2681,7 @@ sub csvupload_fields {
 	    ['starttime','Start Time of slot'],
 	    ['endtime','End Time of slot'],
 	    ['startreserve','Reservation Start Time'],
+            ['endreserve','Reservation End Time'],
             ['reservationmsg','Message when reservation changed'],
 	    ['ip','IP or DNS restriction'],
 	    ['proctor','List of proctor ids'],
@@ -2415,8 +2755,12 @@ sub csv_upload_assign {
 	}
 
 	if ($entries{$fields{'startreserve'}}) {
-	    $slot{'startreserve'}=
-		&UnixDate($entries{$fields{'startreserve'}},"%s");
+            my $date = &UnixDate($entries{$fields{'startreserve'}},"%s");
+            if ($date eq '') {
+                push(@errors,"$name -- No reservation start time set for slot -- value provided had invalid format");
+            } else {
+                $slot{'startreserve'} = $date;
+            }
 	}
 	if (defined($slot{'startreserve'})
 	    && $slot{'startreserve'} > $slot{'starttime'}) {
@@ -2424,6 +2768,20 @@ sub csv_upload_assign {
 	    next;
 	}
 
+        if ($entries{$fields{'endreserve'}}) {
+            my $date = &UnixDate($entries{$fields{'endreserve'}},"%s");
+            if ($date eq '') {
+                push(@errors,"$name -- No reservation end time set for slot -- value provided had invalid format");
+            } else {
+                $slot{'endreserve'} = $date;
+            }
+        }
+        if (defined($slot{'endreserve'})
+            && $slot{'endreserve'} > $slot{'starttime'}) {
+            push(@errors,"$name not created -- Slot's reservation end time is after the slot's start time.");
+            next;
+        }
+
         if ($slot{'type'} eq 'schedulable_student') {
             if ($entries{$fields{'reservationmsg'}}) {
                  if (($entries{$fields{'reservationmsg'}} eq 'only_student') ||
@@ -2444,14 +2802,46 @@ sub csv_upload_assign {
 		$slot{$key}=$entries{$fields{$key}};
 	    }
 	}
-
+        if ($entries{$fields{'allowedusers'}}) {
+            $entries{$fields{'allowedusers'}} =~ s/^\s+//;
+            $entries{$fields{'allowedusers'}} =~ s/\s+$//;
+            my @allowedusers;
+            foreach my $poss (split(/\s*,\s*/,$entries{$fields{'allowedusers'}})) {
+                my ($possuname,$possudom) = split(/:/,$poss);
+                if (($possuname =~ /^$match_username$/) && ($possudom =~ /^$match_domain$/)) {
+                    unless (grep(/^\Q$poss\E$/,@allowedusers)) {
+                        push(@allowedusers,$poss);
+                    }
+                }
+            }
+            if (@allowedusers > 0) {
+                $slot{'allowedusers'} = join(',',@allowedusers);
+            }
+        }
+        if ($entries{$fields{'allowedsections'}}) {
+            $entries{$fields{'allowedsections'}} =~ s/^\s+//;
+            $entries{$fields{'allowedsections'}} =~ s/\s+$//;
+            my @allowedsections;
+            foreach my $poss (split(/\s*,\s*/,$entries{$fields{'allowedsections'}})) {
+                if (($poss !~ /\W/) && ($poss ne 'none')) {
+                    unless (grep(/^\Q$poss\E$/,@allowedsections)) {
+                        push(@allowedsections,$poss);
+                    }
+                }
+            }
+            if (@allowedsections > 0) {
+                $slot{'allowedsections'} = join(',',@allowedsections);
+            }
+        }
 	if ($entries{$fields{'uniqueperiod'}}) {
-	    my ($start,$end)=split(',',$entries{$fields{'uniqueperiod'}});
-	    my @times=(&UnixDate($start,"%s"),
-		       &UnixDate($end,"%s"));
-	    $slot{'uniqueperiod'}=\@times;
+            my ($start,$end)= map { &UnixDate($_,"%s"); } split(',',$entries{$fields{'uniqueperiod'}});
+            if (($start ne '') && ($end ne '')) {
+                $slot{'uniqueperiod'}=[$start,$end];
+            } else {
+                push(@errors,"$name -- Slot's unique period ignored -- one or both of the comma separated values for start and end had an invalid format");
+            }
 	}
-	if (defined($slot{'uniqueperiod'})
+	if (ref($slot{'uniqueperiod'}) eq 'ARRAY' 
 	    && $slot{'uniqueperiod'}[0] > $slot{'uniqueperiod'}[1]) {
 	    push(@errors,"$name not created -- Slot's unique period start time is later than the unique period's end time.");
 	    next;
@@ -2462,6 +2852,9 @@ sub csv_upload_assign {
 	$r->rflush();
 	$countdone++;
     }
+    if ($countdone) {
+        &Apache::lonnet::devalidate_slots_cache($cname,$cdom); 
+    }
     $r->print('<p>'.&mt('Created [quant,_1,slot]',$countdone)."\n".'</p>');
     foreach my $error (@errors) {
 	$r->print('<p><span class="LC_warning">'.$error.'</span></p>'."\n");
@@ -2513,6 +2906,7 @@ sub handler {
 
     my $vgr=&Apache::lonnet::allowed('vgr',$env{'request.course.id'});
     my $mgr=&Apache::lonnet::allowed('mgr',$env{'request.course.id'});
+    my (%slots,$consumed_uniqueperiods);
     if ($env{'form.command'} eq 'showslots') {
         if (($vgr ne 'F') && ($mgr ne 'F')) {
             $env{'form.command'} = 'manageresv'; 
@@ -2533,9 +2927,14 @@ sub handler {
         if (ref($brcrum) eq 'ARRAY') {
             push(@{$brcrum},{href=>"/adm/slotrequest?command=showresv",text=>$title});
         }
-    } elsif ($env{'form.command'} eq 'manageresv') {
-        $title = 'Manage Reservations';
-        $brcrum =[{href=>"/adm/slotrequest?command=manageresv",text=>$title}];
+    } elsif (($env{'form.requestattempt'}) || ($env{'form.command'} eq 'manageresv')) {  
+        if ($env{'form.command'} eq 'manageresv') {
+            $title = 'Manage Reservations';
+            $brcrum =[{href=>"/adm/slotrequest?command=manageresv",text=>$title}];
+        }
+        my ($cnum,$cdom)=&get_course();
+        %slots = &Apache::lonnet::get_course_slots($cnum,$cdom);
+        $consumed_uniqueperiods = &get_consumed_uniqueperiods(\%slots);
     } elsif ($vgr eq 'F') {
         if ($env{'form.command'} =~ /^(slotlog|showslots|uploadstart|csvuploadmap|csvuploadassign|delete|release|remove_registration)$/) {
             $brcrum =[{href=>"/adm/slotrequest?command=showslots",
@@ -2555,14 +2954,27 @@ sub handler {
             if (ref($brcrum) eq 'ARRAY') {
                 push(@{$brcrum},{href=>"/adm/slotrequest?command=$env{'form.command'}",text=>$crumb_titles{$env{'form.command'}}});
             }
-            
         }
+    } else {
+        $brcrum =[];
     }
-    &start_page($r,$title,$brcrum);
+    my ($symb,$js,$available,$allavailable,$got_slots);
+    $available = [];
+    if ($env{'form.requestattempt'}) {
+        $symb=&unescape($env{'form.symb'});
+        @{$got_slots}=&check_for_reservation($symb,'allslots');
+    }
+    if (($env{'form.requestattempt'}) || ($env{'form.command'} eq 'manageresv')) {
+        $js = &reservation_js(\%slots,$consumed_uniqueperiods,$available,$got_slots,$symb);
+    }
+    &start_page($r,$title,$brcrum,$js);
 
     if ($env{'form.command'} eq 'manageresv') {
+        $allavailable = $available;
+        undef($available);
+        undef($got_slots);
         my $crstype = &Apache::loncommon::course_type();
-        &manage_reservations($r,$crstype);
+        &manage_reservations($r,$crstype,\%slots,$consumed_uniqueperiods,$allavailable);
     } elsif ($env{'form.command'} eq 'showresv') {
         &show_reservations($r,$env{'form.uname'},$env{'form.udom'});
     } elsif ($env{'form.command'} eq 'showslots' && $vgr eq 'F') {
@@ -2619,13 +3031,34 @@ sub handler {
 	    return OK;
 	}
 	if ($env{'form.requestattempt'}) {
-	    &show_choices($r,$symb);
+            $r->print('<div class="LC_left_float">'); 
+	    &show_choices($r,$symb,undef,undef,\%slots,$consumed_uniqueperiods,$available,$got_slots);
+            $r->print('</div><div style="padding:0;clear:both;margin:0;border:0"></div>');
 	} elsif ($env{'form.command'} eq 'release') {
 	    &release_slot($r,$symb);
 	} elsif ($env{'form.command'} eq 'get') {
 	    &get_slot($r,$symb);
 	} elsif ($env{'form.command'} eq 'change') {
-	    if (&get_slot($r,$symb,$env{'form.releaseslot'},1)) {
+            if ($env{'form.nochange'}) {
+                my $slot_name = $env{'form.releaseslot'};
+                my @slots = &check_for_reservation($symb,'allslots');
+                my $msg;
+                if (($slot_name ne '') && (grep(/^\Q$slot_name\E/,@slots))) { 
+                     my %slot=&Apache::lonnet::get_slot($env{'form.releaseslot'});
+                     my $description=&get_description($slot_name,\%slot);
+                     $msg = '<span style="font-weight: bold;">'.
+                            &mt('Unchanged reservation: [_1]',$description).'</span><br /><br />';
+                     my $person = 
+                         &Apache::loncommon::plainname($env{'user.name'},$env{'user.domain'});
+                     my $subject = &mt('Reservation unchanged: [_1]',$description);
+                     my $msgbody = &mt('No change to existing registration by [_1] for [_2].',$person,$description);
+                     $msg .= &slot_change_messaging($slot{'reservationmsg'},$subject,$msgbody,'nochange');
+                } else {
+                    $msg = '<span class="LC_warning">'.&mt('Reservation no longer reported as available.').'</span>';
+                }
+                $r->print($msg);
+                &return_link($r);
+	    } elsif (&get_slot($r,$symb,$env{'form.releaseslot'},1)) {
 		&release_slot($r,$symb,$env{'form.releaseslot'});
 	    }
 	} else {