I am in the UK and want to use Paypal as a payment method.
After taking the order in Zen Cart I want the Credit Card to be authorised but not charged to the customer until the goods have been shipped. I got some great advice from FAQ about this

1. Set the payment module into "Authorize Payment" mode (not "Capture" or "Charge" mode).
2. Prepare the order
3. Calculate true shipping charges.
4. Log in to your Merchant Gateway system. Find the transaction for that customer/order. Update shipping costs if appropriate. Now choose to "Capture" the funds. This charges the card and puts the money in your bank account during the next processing cycle.
5. Ship the goods

So now a couple of questions

1 Is it possible to capture the funds automatically from Paypal when the goods have been shipped in Zen Cart (ie a change in order staus) or do I manually have to go into Paypal and capture them each time a shipment is made .

2 If a card has been authorised for say £100.00 but I only ship say £80.00 how do I do this. What do I do if I ship the other £20.00 at a later date .

Thanks in advance