مشکل با spl_autoload_register

/*
function __autoload($classname)
{
$path = ROOTPATH.'\'.strtolower(str_replace('/','\',$classname)).'.php';
require_once $path;
}
*/

function autoload($classname)
{
$path = ROOTPATH.strtolower(str_replace('/','\',$classname)).'.php';
if (is_readable($path))
{
//retu "yes";
require_once $path;
}
else
{
retu "No";
}
}
spl_autoload_register('autoload');


<?php namespace AppControllers;
use AppController as con ;
class Welcome extends con
{
public function IndexAction($name)
{
echo "Welcome ".$name."To Our Site";
parent::kiarash();
//Controller::show();
}
}
?>

<?php namespace App;
class Controller
{
public function kiarash()
{
echo "salam";
}
}
?>

Class 'AppController' not found in