I need a php script that can CHECK and VALIDATE domain name pageranks. User will not be allowed to do mutiple times of checking within a short period of time ( say, 2 sec - 3 sec each time ) or user needs to fill in ( number/ letter ) image when done certain amount of checking, whichever way is working.
just like following two websites:
[url removed, login to view];links=1
[url removed, login to view]