logout page with redirect back page

 <?php

include 'checkLogin.php';

if (!$admin) {

header("location:./"); // not admin redirect to home page 

}

else // if admin destroy the session logouted and redirected to homepage 

{

    if(isset($_SERVER['HTTP_REFERER'])) 

    {

      $user_referer_link = $_SERVER['HTTP_REFERER'];

    }

session_start();  

session_unset();

session_destroy();

header("location:$user_referer_link");

}

?>