How to read something from $order?

I'm working on a plugin for HikaShop but my problem is that I can't read attributes from $order like the address. Following code is within the 'onAfterOrderCreate(&$order,&$send_email)' function

$hikaFirstname = $order->billing_address->address_firstname; 
$hikaLastname = $order->billing_address->address_lastname; 
$hikaCompany = $order->billing_address->address_company;
$hikaFoo = $order->order_user_id;

echo "<br />".$hikaFoo;
echo "<br />".$hikaFirstname."<br />";
echo "Lastname: ".$hikaLastname."<br />";
echo "Company".$hikaCompany."<br />";

Thanks!

I just made a second look in the var_dump($order) and now I see that the billing_adress is included in the cart-object ... just messend around with the braces :-\