My order #100000010 has 3 items. But when I used this code, it did not echo anything. Where is my mistake

```
<?php   
$id_order = 100000010;
$order = Mage::getModel('sales/order')->load($id_order);
$items = $order->getAllItems();
foreach($items as $i):
  echo $_product = Mage::getModel('catalog/product')
            ->load($i->getProductId())->getSku();
endforeach;?>

```