problem in push notification code in windows 7 app

hi friends,
I am new to window phone apps.. I am working with sample application for push notifications.
http://msdn.microsoft.com/en-us/gg153660.aspx
I am getting the code from here , then i excuted every thing what he suggested , but its throughing error in SendToast(uri,message) method,
I find out the issue,but i am not getting any solution for that.
 In above video i am done the same i started 3 prj at a time , ...