Magento update state based in incrementalId

magento-update-state.php

<?php

error_reporting(E_ALL);
ini_set('display_errors', 1);
require_once 'app/Mage.php';
Mage::app();

echo "Testando<br>";
$order = Mage::getModel('sales/order')->loadByIncrementId('100045842');

$order->setState(Mage_Sales_Model_Order::STATE_NEW, 'pending', "just testing", true);
//$order->setState(Mage_Sales_Model_Order::STATE_PROCESSING, 'processing', "just testing", true);
$order->save();

//$order->sendOrderUpdateEmail(true, "just processing");

echo "finish";