i installed the old library from here:http://pearhub.org/get/facebook-0.1.0.tgz and then extracted the facebook.php file and wrote an index.php file in the same folder with the index .php file just displaying hello "username" but the problem is the index.php when run in browser does not show anythink its blank i have xamp installed on my system please help my index.php code is:

require_once 'facebook.php';

$api_key = 'fda501108b3b955bcf0f87a4008bc786'; $secret = '833b35812a3e6b379a5158b2f3f0611f'; $facebook = new Facebook($api_key, $secret); $user_id = $facebook->require_login(); // Greet the currently logged-in user! echo "

Hello, !

?>