I wont bother you any longer.
You're using EZboards. There is no way you can access that kind of information when you have no access to any of the server-side code or the database.
I don't even think it's possible the way Archangel said. You would need to have something running server-side that would keep track of people coming and going.
If you're serious about running a messageboard, buy some webspace, download one of the open source message board softwares out there, get a book on PHP and go at it.
Otherwise please reserve your attitude for something you know even the slightest bit about.
How much C could a C++ if a C+ could + C?