how to get (ScriptObject)HtmlPage.Window.GetProperty(“Xrm”) in Silverlight Application when it embedded to HTML Page in CRM

dynamic xrmnew = (ScriptObject)HtmlPage.Window.GetProperty("Xrm");
if (xrmnew == null)
{
    HtmlWindow parentWindow = HtmlPage.Window.GetProperty("parent") as HtmlWindow;
    xrmnew = (ScriptObject)parentWindow.GetProperty("Xrm");
}
Guid Id = new Guid(xrmnew.Page.data.entity.getId());