how to handle a 403 error with PHP

Question

I have built a php script that can sometimes have the server returns a 403 error message (forbidden access) because of the length and content of the data sent through the $_

Answer 1

It would be to set up a custom error document for 403 errors in Apache, and point this at a script to handle the error. Refer to the ErrorDocument documentation on how to do this, but it would be something along these lines:

ErrorDocument 403 /custom_403_handler.php