Session Timeout

Question

We are using forms authentication where we have given login Url. When the user is on our site and session time out he redirects to login page.

User comes to our site and after click on some button he will be redirected to other site. When user goes to other site  on session timeout we are not getting any event e.g. session_end. We need some event after session time out of such user. We have to carry certain action for session timeout of such user.


Thanks.