>Hi,
>
>I like to know how can my web based application on ASP.NET able to
>track web user timeout and when user click the 'x' button on the
>top right of the webpage ?
>
>I am using SQL Server 2000 SP4.
>
>Anyone got any suggestion or ways to do it.
>Do I need to use Javascript on this area ?
>
>Thank you

There is a way to determine that IE is being closed in JavaScript.

function onClose()
{
   if(window.screenTop>10000)
      {
         alert("window.onClose works!")
      }
}
window.onunload=onClose

Timeout is set in machine.config and for each application in the web.config. I'm not aware of any events that fire when a session times out.