A login helper to use in conjunction with the login class.

login_helper.php

<?php

define("BASEPATH","pathname");

//To use this include it in the top of all pages you need to protect:
//<?php include_once('login_helper.php');?>

function authenticate($url = 'login.php')
{
	session_start();
	if( $_SESSION['authenticated'] == FALSE)
    {
     	header('Location:login.php');
    }
}

authenticate();