sorry got cut off, all you have to do is replace the http://aa with whatever url you want to re-direct the 'scumware' user to it then sends them to that url instead of your site i use it to send them to a page that says:

'you are using scumware that replaces our ads with the software makers own! please un-install _______ and come back thank you'

This way you can potentially get that surfer back, but if you don't they aren't wasting your content and bandwidth.

thanks for the snippet of code & the explination, it will come in very handy!

cheers,
Luke