hi. what is the online users alogorithm using in forum like vb and phpbb?
I thought to include in each page of the site, a page that make update into the sql every 5 minutes for a record containing IP of the visitor and the time of update. and in the page of viewing online user I see if the IP time is more than 5 minutes, I should not display it, and delete it.

is it correct? or there is another better way?
thank's for advance