User portal as a module: the Cancel button (ticket creation wizard) was not working

git-svn-id: http://svn.code.sf.net/p/itop/code/trunk@3705 a333f486-631f-4898-b8df-5754b55c2be0

application/portalwebpage.class.inc.php

@@ -260,7 +260,7 @@ EOF
 	{
 		var form = $('FORM');
 		form.unbind('submit'); // De-activate validation
-		window.location.href = '?operation=';
+		window.location.href = window.location.href.replace(/[&?]operation=[^&]*/, '');
 		return false;
 	}