In my struts application, how do i maintain session, if a user closes the windows browser instead of clickin on logout button? I am using JSP for for client operations.

The Session will stay alive for 20 minutes (defined in web.xml). You can create a SessionListener that logs a person out when the session gets invalidated, ie expires... There is no way you can logout a user when he closes his browser (onUnload event for example). Attempts have been made, but none is guaranteed to work. That's the nature of a web-app....