php - admin page of website only to be accessed by admin if someone tries to access it , it redirects to login-page -

this code have written

if(!isset($_session['authenticated'])){header("location:login.php");} 

but code not working , being accessed

could set variable true or false?

if ($_session['authenticated']) {    // admin page here... } else {    // redirect page...    header("location: login.php");    die(); } 

edit:

the reason set true or false ca log user out setting false. rather unsetting variable.

edit:

• removed = true not required.

you missed capital l in header function , need kill page once have redirected.

replace

header('location:index.php'); 

with

header("location: login.php"); die();