<?php

set_include_path(realpath('/path/to/lib') . PATH_SEPARATOR . get_include_path());

function autoload($className)
{
		require($className . '.php');
}

spl_autoload_register('autoload');

$Database = new Database();

?>

http://www.brandonsavage.net/making-life-better-with-the-spl-autoloader/

check out why the get_include_path() was appended to the new path.

SPL_autoload example script

php

PHP