knowing whos logged on

[Guest]

Hi all

I want to create a webpage that updates say, every 5 minutes (easy), that
shows me whos logged on to my network.

Any ideas?

I've seen this done on an antivirus program, where it pops up on the server
saying "so and so just logged in" or "so and so logged out".

How does it know that?! Can someone point me in the right direction?

Cheers


Dan