Javascript expert is needed

Hi! I need someone to finish a javascript and run it according to my visitors ip address. The script is already working but it needs a few more feature. Somehow the visitors ip address should be saved, and the javascript should run only for those visitors whose ip address hasn't been saved yet. The script should run when the visitor comes to the page, but it has to allow only one click and after the first click the script has to stop work. That is all guys. Thanks for your bid, Tomi