load facebook php sdk from controller

[eluser]niurexx[/eluser]
i try to load facebook from one of my controller but there is a problem with it.. when i run the code and view it using firebug.. an error 500 internal server error displayed..

my code

Code:

<?php


class facebook extends controller
{
    function __construct()
    {
        parent::controller();
    }
    
    function index()
    {
        require './facebook.php;
    }
}