The kline command that I know is kline user[/b]@host :reason, so where I have that echo, you can insert the appropriate information as you see fit.
As your admin/trainer probably told you when you first got opered, klines (on most IRCds) are for a single server, the one you are opered on. If the person who is flooding services is not on your server, then your kline will not get rid of him. If you are a global operator, a better command would be KILL with a reason telling them to stop flooding services. You probably already know this; do as you see fit.