I've created an order for the customer's cart using the following code (When the customer clicks checkout on the app we're making):
$service = Mage::getModel('sales/service_quote', $quote);
$service->submitAll();
$order = $service->getOrder();
However, when a product is added/removed to the cart, the order items remain the same as before the update. How am I supposed to handle the update to the order? Do I cancel all orders the cart has and create a new one? Or is there a way to properly update the order when a new item is added to the cart?