index.php

<?php
session_start();

error_reporting(E_ALL);
ini_set('display_errors', 1);

$section = array();
$section['logout'] = "logout.php";
$section['register'] = 'register.php';
$section['login'] = 'login.php';
$section['index'] = 'index2.php';
$section['news'] = 'news.php';
$section['about'] = 'about.php';
$section['404'] = '404.php';

include 'header.html'; // doctype, <html> und das komplette <head>-element
echo "    <body>\n";

if(!isset($_SESSION['loggedin']))
{
	$_SESSION['loggedin'] = 1; // ausgeloggt
}


if (isset($_GET['section'], $section[$_GET['section']])) {
    include $section[$_GET['section']];
} else {
    include $section['news'];
}

echo "    </body>\n";
echo "</html>\n";
?>