Help about Password protected server

Hi,

I noticed in the joinServerGui.gui about setting the password for the Connection.

%conn.setJoinPassword($Client::Password);

Can anyone help me to figure out how to implement a password protected server.
I just want to add password for each connection and when a client join the server with
a password, i'll check the password and assign a specific role to that player.

It is also nice it some one can help me giving any idea how can I check the password from the
server side and create specific player according to the server.

Thank you