Login session help

[PRodgers4284]

I need a way of stoping a user on my website from accessing protected pages if they are not logged in, can anyone help? Im using the following code at the start of each page.

 

<?php
session_start(); 
include("database.php");
include("loginemployer.php");
?>

[PRodgers4284]

Ive tried using the code below, but it doesnt work, not sure if im using the redirect header correctly, im putting the code on each protected page, can anyone provide some help or advice?

 

if (!SESSION_username) {
Header("Location: index2.php");
}

[Chris92]

<?php
if( empty($_SESSION['username']) )
{
    header("location: index2.php");
}
?>

[PRodgers4284]

<?php
if( empty($_SESSION['username']) )
{
    header("location: index2.php");
}
?>

 

Thankyou very much, really appreciate your help