No, there is no password (except in really unusual circumstances, eg. deliberate attacs by a l33thaxxor, then the server is pwd'd for a short period of time).
Check that you have the settings correct. You must have a username. However, double usernames are not allowed. Funnily enough though, the second user who connects with the same name is allowed to stay (by default) and the first one gets kicked
Check that your server settings are correct. The server name is irrelevant, but hostname/IP-address is vt.fragmaster.net
The port number is 3808. You can also connect
automatically, by using the direct link at
http://www.fragmaster.net/vt
Note that in the main window (the big white area below name, server and bindings, and next to connect and setup buttons) it should say: "MSG: Server is available. Press connect"