--- rat/lonwrapper.pm	2016/10/31 19:49:05	1.53
+++ rat/lonwrapper.pm	2016/11/29 19:53:58	1.54
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Wrapper for external and binary files as standalone resources
 #
-# $Id: lonwrapper.pm,v 1.53 2016/10/31 19:49:05 raeburn Exp $
+# $Id: lonwrapper.pm,v 1.54 2016/11/29 19:53:58 damieng Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -114,7 +114,7 @@ sub wrapper {
         my $script = &Apache::lonhtmlcommon::scripttag(<<SCRIPT);
         \$(document).ready( function() {
             \$(window).unbind('resize').resize(function(){
-                var header;
+                var header = null;
                 var offset = 5;
                 var height = 0;
                 var hdrtop = 0;
@@ -126,7 +126,7 @@ sub wrapper {
                         header = \$('#LC_breadcrumbs');
                     }
                 }
-                if (header.length) {
+                if (header != null && header.length) {
                     height = header.height();
                     hdrtop = header.position().top;
                 }