Ayuda con redireccion

[urgido]

Código PHP:

session_start();
if(!isset($_SESSION['usr_id']) && !isset($_SESSION['user_name'])){
$_SESSION['redir'] = $_SERVER['HTTP_REFERER'];
$redir = $_SESSION['redir']; 
header('Location: ../Session/loginFrm.php?redir='.$redir); 
     }