--- loncom/homework/radiobuttonresponse.pm	2004/03/05 23:04:31	1.84
+++ loncom/homework/radiobuttonresponse.pm	2004/03/08 23:23:04	1.85
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # mutliple choice style responses
 #
-# $Id: radiobuttonresponse.pm,v 1.84 2004/03/05 23:04:31 albertel Exp $
+# $Id: radiobuttonresponse.pm,v 1.85 2004/03/08 23:23:04 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -29,6 +29,7 @@
 package Apache::radiobuttonresponse;
 use strict;
 use HTML::Entities();
+use Apache::lonlocal;
 
 BEGIN {
     &Apache::lonxml::register('Apache::radiobuttonresponse',('radiobuttonresponse'));
@@ -42,6 +43,7 @@ sub start_radiobuttonresponse {
     push (@Apache::lonxml::namespace,'radiobuttonresponse');
     my $id = &Apache::response::start_response($parstack,$safeeval);
     %Apache::hint::radiobutton=();
+    undef(%Apache::response::foilnames);
     if ($target eq 'meta') {
 	$result=&Apache::response::meta_package_write('radiobuttonresponse');
     } elsif ($target eq 'edit' ) {
@@ -92,6 +94,7 @@ sub end_radiobuttonresponse {
     &Apache::response::end_response;
     pop @Apache::lonxml::namespace;
     &Apache::lonxml::deregister('Apache::radiobuttonresponse',('foilgroup','foil','conceptgroup'));
+    undef(%Apache::response::foilnames);
     return $result;
 }
 
@@ -535,12 +538,17 @@ sub end_foil {
     if ($target eq 'web' || $target eq 'tex' || $target eq 'analyze') {
 	$text=&Apache::lonxml::endredirection;
     }
-    if ($target eq 'web' || $target eq 'grade' || $target eq 'answer'  || $target eq 'tex' || $target eq 'analyze') {
+    if ($target eq 'web' || $target eq 'grade' || $target eq 'answer'
+	|| $target eq 'tex' || $target eq 'analyze') {
 	my $value = &Apache::lonxml::get_param('value',$parstack,$safeeval);
 	if ($value ne 'unused') {
 	    my $name = &Apache::lonxml::get_param('name',$parstack,$safeeval);
-	    my $location =&Apache::lonxml::get_param('location',$parstack,$safeeval);
 	    if (!$name) { $name=$Apache::lonxml::curdepth; }
+	    if (defined($Apache::response::foilnames{$name})) {
+		&Apache::lonxml::error(&mt("Foil name <b><tt>[_1]</tt></b> appears more than once. Foil names need to be unique.",$name));
+	    }
+	    my $location =&Apache::lonxml::get_param('location',$parstack,
+						     $safeeval);
 	    if ( $Apache::radiobuttonresponse::conceptgroup
 		 && !&Apache::response::showallfoils() ) {
 		push @{ $Apache::response::conceptgroup{'names'} }, $name;