LAN with multiple copies of CS?

[.flowers!!]

Can you play LAN with multiple copies of CS? Here at my Dad's house, we have three copies of CS:S, and all the computers are connected. However, we can't seem to get LAN working. Do we need to be on the same Steam name? What do we need to do? Thanks.

 

[$kelet0r]

one computer starts a game and the others can then join
simple as
are you sure you have connected the computers properly - one should be the master computer and the others should be connecting through a router