log off problem!

[wernerh]

I have 5 different sites with different web addresses running on my webserver, all of these sites require a user to log on, (I store names etc. in session variables)
I have managed to let the user log in at one site and stay logged in throughout the rest of the sites by using parameters!

My problem is when a user logs out on one site all the session variables on the other sites should abandon too! How do I accomplish this????

[Mark Sreeves]

Just a guess here because I've never done it...
instead of using session variables use a unique ID which is stored in a hidden field and passed in the query string.

Then have a database which is common to all 5 sites/servers and contains a "loggedin" status flag against the ID. Each page checks the status and the status flag is set to false when the user logs out of any one of the 5 sites.