How to show Session Expiry Message alert and Extend Existing Session in ASP.NET

refer the following link for Session time out alert and extend session timeout    by using DevexpressPopup control.


http://www.devexpress.com/Support/Center/e/E3302.aspx


refer the following link for Session time out alert and extend session timeout by using jquery

http://philpalmieri.com/2009/09/jquery-session-auto-timeout-with-prompt/