How do I join a chat room from the messenger on my mobile phone?

I already have yahoo messenger on my t-mobile phone. (Sidekick I'd) and I wanted to join a chat room but I can't figure it out ther is no chat room option on my phone. Please help!How do I join a chat room from the messenger on my mobile phone?more importantly, y would u want to join a chat room?How do I join a chat room from the messenger on my mobile phone?i dont think u canHow do I join a chat room from the messenger on my mobile phone?que demonios hago aqui!!!!????????????