<?php
echo includeContent($_GET['x']);
function includeContent($x) {
// Default page if $x doesn't exist or
// isn't specified
$default = 'index';
// File extension of the file to include
// i.e. given $x=info we want to include
// info.php
$extension = '.php';
// Only allow alphanumeric characters
$x = preg_replace('/[^a-z0-9]/i', '', $x);
// If $x isn't set then or $x doesn't exist
// use the default page
if ( !isset($x) || !file_exists($x.$extension) )
$x = $default;
// Just incase $default doesn't exist
if (file_exists($x.$extension))
include($x.$extension);
}
?>