Xml code for im gateway

Hi

I am working with flex and jabber server ( very new in jabber field). I have completed connection, roster setting, presence setting and etc with the help of small chunk of xml codes (not using any library ). Now I am trying to use yahoo transport option. I have tried few xml codes but with no result. I have already installed imgateway over open fire server.

Please help me about the xml code by which i can use this option.

Gunjan