Forums Scripts & Popups hide 'join' and 'quit' messages

I think I understand the logic but it's the syntax that I'm not familiar with.
should there be parenthesis around the $nick == obnoxisousnick ???
or should it be ($the nick I want to not see) as in ($willy)???
as example
on ^*:JOIN:#: if ($willy) haltdef
or
on ^*:JOIN:#: if ($nick == willy) haltdef

And I think the last line of your script says that if he changes his nick to anything else, then that one is the nick that will be not seen???

Sorry but I'm really a beginner.