Lets say I have a website www.mySite.com and there are a lot of pages whose links are www.mySite.com\contact.php and www.mySite.com\about.php.
What if I want that when someone enters a direct link like www.mySite.com\about.php instead of opening that page it should go to a page myPolicy.php and then myPolicy.php may\may not refer the user to the requested page....
HOW to do IT
One method I thought is have a PHP page myPolicy.php and include\require it in beginning of every page so than I can decide weather to continue the requested page or redirect somewhere else or not.... 
Is that okay?
Is there a better way or some best practice for this kind of thingy?