set_include_path

<?php 
 
function __autoload($className) 
{
    $path = str_replace('_', DIRECTORY_SEPARATOR, $className).'.php';
    
    if(file_exists($path))
    {
        include ($path);
    }
}

<?php
    error_reporting(E_ALL|E_STRICT);
    //set_error_handler("error_handler");
    date_default_timezone_set('Europe/London');
    include('..'.DIRECTORY_SEPARATOR.'libs'.DIRECTORY_SEPARATOR.'App'.DIRECTORY_SEPARATOR.'config.php');
    include('..'.DS.'libs'.DS.'App'.DS.'Autoloader.php');
 
    $paths = implode(PATH_SEPARATOR,
                    array (get_include_path(),
                    realpath('..'.DS.'libs'.DS),
                    realpath('..'.DS.'application'.DS.'models'.DS)));      
    set_include_path($paths);
$site_path = realpath(dirname(__FILE__).DS).DS;
    define ('site_path', $site_path);
    
    
    $reg = App_Registry::getInstance();

Class 'App_Registry' not found in /media/data2/web/public/index.php on line 25

$reg = App_Registry::getInstance();

/**
 * Set the initial include path
 */
 
set_include_path(implode(PATH_SEPARATOR, array(
    realpath(dirname(__FILE__) . '/library'),
    get_include_path(),
)));