tcp/udp multicast/broadcast

I'm making a game that requires the connection of two or more players. at the moment if two people are on a LAN or internet they have to specify their addresses explicitly.

I want to know how to broadcast if a player is available on a network, so the user can just click the game name. I thought there where broadcast address for UDP (like 255.255.255.255 or something)

help?

>>2
ah, I've done it, thanks alot =D