Edit file File name : processScreenSize.php Content :<?php /** * Created by PhpStorm. * User: lewis * Date: 16/02/15 * Time: 15:42 */ if($_SESSION['screen_height'] != $_POST['height'] || $_SESSION['screen_width'] != $_POST['width']){ $_SESSION['screen_height'] = $_POST['height']; $_SESSION['screen_width'] = $_POST['width']; } Save