At work we have a network of 6 computers.. 1 win 98, 4 win 2000, 1 win xp...

they asked me if i could build something that would enable the 6 computers to chat, similar to msn or yahoo, but only within the network..

Not all of us have msn or yahoo..

Now i don't have the foggiest idea how to even go about that..

Was wondering if anyone has come across a program that would do this??