Don't forget, because $_REQUEST is a different variable than $_GET and $_POST, it is treated as such in PHP -- modifying $_GET or $_POST elements at runtime will not affect the ellements in $_REQUEST, nor vice versa.
$_GET['foo'] = 'a';
$_POST['bar'] = 'b';
var_dump($_GET); var_dump($_POST); var_dump($_REQUEST); ?>
If you want to evaluate $_GET and $_POST variables by a single token without including $_COOKIE in the mix, use $_SERVER['REQUEST_METHOD'] to identify the method used and set up a switch block accordingly, e.g:
case 'GET': $the_request = &$_GET; break;
case 'POST': $the_request = &$_POST; break;