Reading your previous messages and mainly this one
www.hikashop.com/forum/payment-methods/8...you-page.html#216933
it seems that you're using that code somewhere with specific tags, not in a HikaShop view file.
In that case, before you try using HikaShop functions, you need to load HikaShop itself if it isn't loaded.
It would explain why you get a blank page.
So you'll want to try something like that:
<?php
if(!defined('DS'))
define('DS', DIRECTORY_SEPARATOR); if(!include_once(rtrim(JPATH_ADMINISTRATOR,DS).DS.'components'.DS.'com_hikashop'.DS.'helpers'.DS.'helper.php')) return true;
$app =JFactory::getApplication();
$order_id = $app->getUserState('com_hikashop.order_id');
echo $order_id; // To display the order id
$orderClass = hikashop_get('class.order');
$fullOrder = $orderClass->get($order_id); // To get all the order
echo $fullOrder->order_number; // To display the order number
?>
PS: please remember that we provide user support. Not customization support. This is clearly out of the services you've been paying for the last 4 years. We've already got way above what we are supposed to do here. If you need someone to code something for you, please contact our partners or post on our commercial jobs forum.