Originally Posted by Andrew

Try:
$_GET is an array, so you have to use count() to count how many parts to the array there are.

Originally Posted by xenon

It's simple: just get the one you're interested the most in. If the user id is more important than the group, then take only the user id and ignore the rest. Or, you could go for showing the user an error, or perhaps even redirecting them somewhere. As long as the request is not done via the website urls, you can do what ever you want with the unwanted requests.