With new technology making the web a viable option for more and more applications, we are now seeing the web browser take over for the traditional desktop. Developers making this transition, quickly learn about some of the key differences between the two paradigms. One of the issues they are often forced to deal with is Session expiration. Out of the box, ASP.NET and IIS typically allow only 20 minutes of idle time before the session expires. This can be configured, but knowing that the session expired, or redirecting to a particular page often comes in handy. One way to do this is to add a cookie during the Session_Start method of the global.ascx.cs file, and then check for that same cookie the next time a session is created. If the cookie is there, the session either timed out, or was reset.