Different header if signed-in or not

Is there anyway I can detect if user is login or not?

whenever I successfuly logged in, my header changes into header-signedinphp and if click the index page again, my header changes ito header.php .

I didnt put any session_destroy() on the index page.

<?php 

if(isset($_SESSION['email_address'])){
require_once("template/header-signedin.php");
}else{  
require_once("template/header.php");
}
?>