Magento / PHP - 如何按顺序获取自定义客户属性

i am using Magento 1.9.0.1 and i am developing a custom extension.

Right now i am stuck at the following thing.

Like this i use to get the customers name from an order:

$CustomerName = $observer->getOrder()->getBillingAddress()->getName();

I have custom customer attribute called sms_on_order_change and i am trying to get the value of it like that:

$SMSOnStatusChange = $observer->getResource()->getAttribute('sms_on_order_change')->getFrontend()->getValue();

But it is not working.

Here is the extension that i am using for the creation of custom customer attributes: http://www.magentocommerce.com/magento-connect/manage-customer-attributes.html

So guys, can you help me out so i can get the value of this custom attribute ?

Thanks in advance!

This should help you out:

//get order from observer
$order = $observer->getOrder();
// get customer id from order
$customer_id = $order->getCustomerId();

// condition only necessary if guest orders are allowed
if ($customer_id)
{
    $_customer = Mage::getModel('customer/customer')->load($customer_id);
    $sms_on_order_change = $_customer->getData('sms_on_order_change');
}