Quake 3 multiplayer troubles?

i recently downloaded the demo of quake 3 (couldn't find full version online, if anyone knows where i could grab it that would rock).only problem is when i try to play multiplayer it doesn't find any servers, and i'm sure there are some out there.is there something wrong with "Mplayer" (i think that was the name of the service) or is there something i have to do to make it work?