Total number of Facebook group members

[Mad_Griffith]

Hello, I am trying to understand how to display the total number of Facebook group members. I managed to put this code together, but when I load it the page is blank:

<?php
    require('facebook.php');
    $config = array(
        'appId' => 'MYAPPID',
        'secret' => 'MYSECRETID',
        'cookie' => true
    );
    $facebook = new Facebook($config);
    $query = urlencode('SELECT count(uid) from group_member WHERE gid = MYGROUPID limit 500 offset 500');
    try {
        $fbData = $facebook->api("/fql?q={$query}");
    } catch (FacebookApiException $e) {
        $fbData
		 = $e->getResult();
    };
  var_dump($fbData);
?>