--- loncom/homework/optionresponse.pm	2004/03/25 16:55:16	1.105
+++ loncom/homework/optionresponse.pm	2004/04/16 22:25:13	1.106
@@ -1,7 +1,7 @@
 # LearningOnline Network with CAPA
 # option list style responses
 #
-# $Id: optionresponse.pm,v 1.105 2004/03/25 16:55:16 albertel Exp $
+# $Id: optionresponse.pm,v 1.106 2004/04/16 22:25:13 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -284,6 +284,27 @@ sub displayanswers {
   return $result;
 }
 
+sub check_for_invalid {
+    my ($names,$options) = @_;
+    my %bad_names;
+    foreach my $name (@{ $names }) {
+	my $value=$Apache::response::foilgroup{$name.'.value'};
+	my $found=0;
+	foreach my $option (@{ $options }) {
+	    if ($value eq $option) { $found=1; }
+	}
+	if (!$found) { $bad_names{$name}=$value; }
+    }
+    if (%bad_names) {
+	my $error=&mt('The question can not be gotten correct, '.
+	    'the following foils in the <optionresponse> '.
+	    'have invalid correct options').' <br /><tt>'.
+	    join('<br />',(map { $_=&mt("[_1] with value [_2]",$_,$bad_names{$_}) } (keys(%bad_names)))).
+	    "</tt>";
+	&Apache::lonxml::error($error);
+    }
+}
+
 sub displayfoils {
   my ($target,$max,$randomize,@opt)=@_;
   if (!defined(@{ $Apache::response::foilgroup{'names'} })) {return;}
@@ -295,6 +316,7 @@ sub displayfoils {
   my $displayoptionintex=1;
   my @alphabet = ('A'..'Z');
   my @whichopt = &whichfoils($max,$randomize);
+  &check_for_invalid(\@whichopt,\@opt);
   my $part=$Apache::inputtags::part;
   my $id=$Apache::inputtags::response[-1];
   my $break;