xml-rpc 2 questions

Which is the 'correct' xml-rpcclient.js library to use?

The one that comes with firefox 0.9 or mozblogs?

The reason I ask is I've been using the mozblog file which works but the one 
shipped with firefox doesn't.

Does anyone have an example of how to use username,password with the xml-rpc 
library to provide authetication?

Guy