<?php
$app_id = "YOUR_APP_ID";
   $app_secret = "YOUR_APP_SECRET";
   $my_url = "YOUR_URL";
session_start();
   $code = $_REQUEST["code"];
if(empty($code)) {
     $_SESSION['state'] = md5(uniqid(rand(), TRUE)); //CSRF protection
     $dialog_url = "https://www.facebook.com/dialog/oauth?client_id=" 
       . $app_id . "&redirect_uri=" . urlencode($my_url) . "&state="
       . $_SESSION['state'];
echo("<script> top.location.href='" . $dialog_url . "'</script>");
   }
if($_REQUEST['state'] == $_SESSION['state']) {
     $token_url = "https://graph.facebook.com/oauth/access_token?"
       . "client_id=" . $app_id . "&redirect_uri=" . urlencode($my_url)
       . "&client_secret=" . $app_secret . "&code=" . $code;
$response = file_get_contents($token_url);
     $params = null;
     parse_str($response, $params);
$graph_url = "https://graph.facebook.com/me?access_token=" 
       . $params['access_token'];
$user = json_decode(file_get_contents($graph_url));
     echo("Hello " . $user->name);
   }
   else {
     echo("The state does not match. You may be a victim of CSRF.");
   }
?>