Getting started with the Facebook PHP SDK v4.1

fb_php_sdk_4.1.php

<?php

// Set the location of the Facebook PHP SDK - this should point to directory containing autoload.php
define( 'FACEBOOK_SDK_V4_SRC_DIR', './Facebook/' );

// include required files from Facebook SDK
require_once( 'Facebook/autoload.php' );

// start the session
session_start();