SessionId problem

Hi,

In my login page after a user log on to a web app i have a code which write in to the database login data:
- User Id
- Session Id
- Date
- Status: 'IN'
etc.

Next, When user click loginstatus control, apart from loging off the user i abandon the session.

In global.asax in session end module I have a code which writes to the database same data with status = 'OUT'.

I have a problem, because i found out that when a user log off from the app, and then log in one more time from the same browser window he has the same sessionId as he had in previous session.

Why does the session doesn`t change even thought I called session.abandon?

Are you using ASP.NET Membership provider if so you can use FormsAuthentication.SignOut
Else you can try Session.Clear