Logout isn't logging out

[MystedVeil]

I am having an issue with this as once an individual is logged in it will not logout, even when clicking the Logout link.
Here is my code for the logout:

$page_title = 'Logout';
include_once ('includes/header.html');

// If no first_name variable exists, redirect the user.
if (!isset($_SESSION['member'])) {

header ("Location: index.php");
ob_end_clean(); // Delete the buffer.
exit(); // Quit the script.

} else { // Logout the user.

$_SESSION = array(); // Destroy the variables.
session_destroy(); // Destroy the session itself.
setcookie (session_name(), '', time()-300, '/', '', 0); // Destroy the cookie.

}

// Print a customized message.
echo "You are now logged out.";

include ('includes/footer.html'); // Include the HTML footer.

[bpat1434]

You destroy the session before setting a cookie back to null. If the session is destroyed, how will it know what session_name to use?

Try:

$_SESSION = array();
setcookie(session_name(), '', time()-300, '/', '', 0);
session_destroy();