How does "Live Chat" works?

[NiGHTsC]

I just tried it and I can't get it works.
Eeverytime I get into it, it give me an error message

[00:31] Your username is invalid.
[00:31] Connect with your real username, in lowercase.
[00:31] If your mail address were [email protected], your username would be foo.
[00:31] Error : Closing Link: NiGHTsC by ign.ie.quakenet.org (USER: Bad username)
[00:31] Disconnected from irc.quakenet.org