PHP programming forum. Ask questions or help people concerning PHP code. Don't understand a function? Need help implementing a class? Don't understand a class? Here is where to ask. Remember to do your homework!
Be aware that if people don't add you their favorites on their own, they don't want you there. If you force your way into it, you look like a spammer. In fact, I'm pretty sure that makes you a spammer.
There are different methods for different browsers, but I would sincerely recommend you take the advice of the others in this thread and offer a link for the user instead of doing it programmatically.