On Silverlight page: Xrm object is not available after Rollup 13 update. Working fine with RU11

Scenario:

• In “Save & Close” and “Save and New”. We want to call Silverlight page using HTML page that in turn calls WCF Service.

Issue:

• We have added the logic in on Load event; that loads Silverlight page which retrieves the saved value and passes to WCF service.
• In case of Save & Close” and “Save and New” the page will be closed. The onLoad event will not be triggered.

Query:

• We used this fetch logic in Silverlight as in UR 13 we were not able to get the Xrm object?
• dynamic xrm = HtmlPage.Window.GetProperty("Xrm");   
• The same code was working for UR 12.