--- loncom/homework/chemresponse.pm	2006/08/01 14:04:59	1.70
+++ loncom/homework/chemresponse.pm	2007/04/18 00:19:37	1.72
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # chemical equation style response
 #
-# $Id: chemresponse.pm,v 1.70 2006/08/01 14:04:59 albertel Exp $
+# $Id: chemresponse.pm,v 1.72 2007/04/18 00:19:37 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -467,7 +467,7 @@ sub start_reactionresponse {
 		&Apache::lonxml::default_homework_load($safeeval);
 	    }
 	    @Apache::scripttag::parser_env = @_;
-	    $Apache::inputtags::answertxt{$id}=&Apache::run::run("return &chemparse(q\0$ans\0);",$safeeval);
+	    $Apache::inputtags::answertxt{$id}=[&Apache::run::run("return &chemparse(q\0$ans\0);",$safeeval)];
 	}
     } elsif ($target eq "edit") {
 	$result .=&Apache::edit::tag_start($target,$token);
@@ -542,6 +542,9 @@ sub end_reactionresponse {
 	}
 	$result.=&Apache::response::answer_footer('reactionresponse');
     }
+    if ($target eq 'web') {
+	&Apache::response::setup_prior_tries_hash(\&format_prior_response_reaction);
+    }
 
     if ($target eq 'grade' || $target eq 'web' || $target eq 'answer' || 
 	$target eq 'tex' || $target eq 'analyze') {
@@ -551,6 +554,12 @@ sub end_reactionresponse {
     return $result;
 }
 
+sub format_prior_response_reaction {
+    my ($mode,$answer) =@_;
+    return '<span class="LC_prior_reaction">'.
+	    &HTML::Entities::encode($answer,'"<>&').'</span>';
+}
+
 sub start_chem {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
     my $result = '';