Set magento orders to complete.

complete.php

<?php
require_once 'app/Mage.php';
$app = Mage::app();

Mage::register('isSecureArea', true);
Mage::app()->setCurrentStore(Mage_Core_Model_App::ADMIN_STORE_ID);

$order = Mage::getModel('sales/order')->loadByIncrementId('100000266');
$order->setData('state', 'complete');
$order->setStatus('complete');
$history = $order->addStatusHistoryComment('Order was set to Complete by our automation tool.', false);
$history->setIsCustomerNotified(false);
$order->save();