The best logout page for real security for your user.

logout.php

<?php session_start();

	$siteprot = $_SERVER['REQUEST_SCHEME'] . '://';
	$sitehost = $_SERVER['HTTP_HOST'];
	$siteuri =  $_SERVER['REQUEST_URI'];

	if(!$_COOKIE['SITEINDEX']) {
	    setcookie('SITEINDEX', max(explode('/', dirname($_SERVER['PHP_SELF']))));
	    $siteindex = '/' . max(explode('/', dirname($_SERVER['PHP_SELF']))) . '/';
    } else {
    	$siteindex = '/' . $_COOKIE['SITEINDEX'] . '/'; }

	$siteurl = $siteprot . $sitehost . $siteindex; ?>

<?php $_SESSION = array();

			if($_COOKIE[session_name()]) {
				setcookie(session_name(), '', time()-42000, '/'); }

			foreach($_SESSION as $unset_session => $unset_value) {
				$_SESSION[$unset_session] = $unset_value; }

			foreach($_COOKIE as $unset_cookie => $unset_value) {
				setcookie($unset_cookie, $unset_value, time()-42000, '/'); }

			session_destroy();

			header('Location: ' . $siteurl); ?>