Why don $HTTP_POST_VARS, $HTTP_GET_VARS and all the $HTTP_*_VARS predefined array work?
The use of $HTTP_POST_VARS, $HTTP_GET_VARS and the other $HTTP_*_VARS predefined arrays has been deprecated since PHP 5.0.0. From PHP 4.1.0 you can use the superglobals ($_POST, $_GET and so on) in the place of the long predefined arrays. If your code still relays on the long predefined array you can enable them editing the php.ini.
