How to create Session Timeout alert box and Redirect to Login.aspx page in ASP.NET

ASP.NET allows you to save values by using session state, which is an instance of the System.Web.SessionState.HttpSessionState class, for each active Web Application session. If different users are using your application, each user session will have a different session state. You can use session state to accomplish the following tasks:

1. Uniquely identify browser or client-device requests and map them to an individual session instance on the server.
2. Store session-sepcific data on the server for user across multiple browser or client-device requests within the same session.
3. Raise appropriate session management events. In addition, you can write application code that make use of these event.

So, here is how you can redirect a user who's session time is out. Copy the JavaScript and HTML code in you application.

Copy this HTML code in your application.

Your Session will expirein  12sec and you will belogged out.Click here to stay logged in.Click here to Sign Out.