Well u do know thats not going to work because ... what happends if theirs a netsplit and a server comes back up and lets say 100 people join at the same time after 4nicks you are gonna lock them out
Your better off doing like when someone joins set a +l of 15 more then the users their like if u have a 100 users set it to +l 115 then when like 3 more users join set it to +l 120 or what not how to script that i havent got a clue but thats my idea...
