--- loncom/xml/lonplot.pm	2013/01/31 17:10:38	1.172
+++ loncom/xml/lonplot.pm	2013/02/04 17:23:44	1.173
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Dynamic plot
 #
-# $Id: lonplot.pm,v 1.172 2013/01/31 17:10:38 raeburn Exp $
+# $Id: lonplot.pm,v 1.173 2013/02/04 17:23:44 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -1714,7 +1714,7 @@ sub generate_tics {
     my $result   = '';
 
 
-    if (defined %$spec) {
+    if ((ref($spec) eq 'HASH') && (keys(%{$spec}) > 0)) {