--- loncom/homework/rankresponse.pm	2010/12/19 00:48:50	1.64
+++ loncom/homework/rankresponse.pm	2011/06/07 17:27:37	1.65
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # rank style response
 #
-# $Id: rankresponse.pm,v 1.64 2010/12/19 00:48:50 raeburn Exp $
+# $Id: rankresponse.pm,v 1.65 2011/06/07 17:27:37 www Exp $
 # Copyright Michigan State University Board of Trustees
 #
 # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
@@ -538,6 +538,9 @@ sub end_foil {
 		$name=$Apache::lonxml::curdepth;
 	    }
 	    &Apache::lonxml::debug("Using a name of :$name:");
+            if ($name eq "0") {
+                &Apache::lonxml::error(&mt('Foil name [_1] is not supported. Please choose another name.','<b><tt>'.$name.'</tt></b>'));
+            }
 	    if (defined($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>'));
 	    }