--- loncom/homework/optionresponse.pm	2011/03/07 19:42:21	1.175
+++ loncom/homework/optionresponse.pm	2011/06/07 17:27:37	1.176
@@ -1,7 +1,7 @@
 # LearningOnline Network with CAPA
 # option list style responses
 #
-# $Id: optionresponse.pm,v 1.175 2011/03/07 19:42:21 www Exp $
+# $Id: optionresponse.pm,v 1.176 2011/06/07 17:27:37 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -850,6 +850,9 @@ sub end_foil {
 	  &Apache::lonxml::warning(&mt('Foils without names exist. This can cause problems to malfunction.'));
 	  $name=$Apache::lonxml::curdepth;
       }
+      if ($name eq "0") {
+          &Apache::lonxml::error(&mt('Foil name [_1] is not supported. Please choose another name.','<b><tt>'.$name.'</tt></b>'));
+      }
       &Apache::lonxml::debug("Using a name of :$name:");
       if (defined($Apache::response::foilnames{$name})) {
 	  &Apache::lonxml::error(&mt("Foil name [_1] appears more than once. Foil names need to be unique.",'<b><tt>'.$name.'</tt></b>'));