re:
!> how do I capture which users have just closed the browser window
You can't, unless you're using the Membership class for logins.
re:
!> those who have left the browser open
You can't.
re:
!> whose session has timed out?
You *can*, by capturing the Session_OnEnd events, but only if you're using InProc
session state management and relying on counting the number of sessions active.
If you're using SQL Server session state management or State Server,
the Session_OnEnd event ( also referred to as Session_End ) will never fire.
So, at most, you can keep track of how many sessions are active,
but not how many users are actually connected, if you rely on counting active sessions.
Btw, you didn't say whether you're using the Membership class for logins, but if you are,
you can trap the number of users logged in with Membership.GetNumberOfUsersOnline().
Simple, huh ? ...but it only works if you're using logins and Membership.
Juan T. Llibre, asp.net MVP
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