Need help with a java chat software!!! Anyone pls give ideas

I need to implement a chat protocol with sockets for my course!!

As of now i have only got to the simple client server application with sockets and have a user interface with panels.

How could I proceed...

How should i use login names and passwords?

Should i use if else loops to specify :

various headers like

login

pass

send

exit

if you could point out som esite that will be helpful or even a book it would be of great help!!

[496 byte] By [icejava] at [2007-9-30 23:18:14]