Poll users on Windows Server from Linux

Ok this probably sounds fishier than it really is, I am making a "who is online" script in PHP. This essentially lights up a little "in" sign next to a persons picture on a website when they are available.

Does anyone know of a way to poll user accounts from a Windows 2k3 server from linux? What I am looking for is something similair to psloggedon.exe from sysinternals, but just on a different platform. If I can make it so as soon as they login to the domain they are marked available, it will save people time. All this for a little lite up button.....


Thanks in advance.

have no idea.
But
i have a simpler idea to do that: login and logoff scripts, writing on a database. what about this idea?

I tried creating a login script that fired up firefox and would execute a php script, but it didnt sem to work, could have been more a problem with my scripting....I just prefer to use mysql on linux and dont want to add db traffic to our domain server. perhaps I will investigate the login scripts once again.

thanks.