--- loncom/auth/lonlogin.pm	2013/01/23 15:26:37	1.154
+++ loncom/auth/lonlogin.pm	2013/01/28 02:00:58	1.155
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Login Screen
 #
-# $Id: lonlogin.pm,v 1.154 2013/01/23 15:26:37 raeburn Exp $
+# $Id: lonlogin.pm,v 1.155 2013/01/28 02:00:58 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -654,7 +654,8 @@ sub contactdisplay {
 <script type="text/javascript">
 // <![CDATA[
 function helpdesk() {
-    var codedom = document.client.udom.value;
+    var possdom = document.client.udom.value;
+    var codedom = possdom.replace( new RegExp("[^A-Za-z0-9.\\-]","g"),'');
     if (codedom == '') {
         codedom = "$authdomain";
     }