Handling uncontrolled Logoff from Website

How to keep track on logged-in users, even if they close the browser

[beath]

hiya

i'm having a problem with a counter that shows the numbers of logged-in users. the bookkeeping works fine, if the users logoff from the website by using the logoff-button. but if they just close the browser, they still remain as active. this is not exactly a language-based problem, more a conceptual problem.

any ideas?

thanks and hang loose
beat

ps: i'm aware of the fact, that in general this is a client-side problem, but perhaps there are any ideas how to deal it with a server-script...)

[neo_brown]

Im no expert here and my response my not be the solution, it may even be ignorant, so sorry in advance if it is.
But cant you just give them a time out?