Error when coupon price is greater than the total price in cart

[amyth91]

Hi guys,

I've recently installed a shopping cart using joomla 2.5 and virtuemart 2.0.

after, i've done and the website was online for testing, the client came to me, with a question asking "what happens if a coupon price is higher that the amount in the shopping cart".

Well, i did not what to answer, so i said i'll have to see and let you know, i tried this and the system comes up with an error.

I created a coupon worth $500 and then purchased item worth $300 with it. The system at the checkout where you enter coupon code, subtracts $300 from the cart and makes the total checkout price $0.

I can successfully proceed to paypal then, but paypal gives an error saying "zero is not a valid amount".

has anyone come across this before.

are there any extension that can handle this situation. or are there any coupon extension that can manage the purchase using coupons. say if i used a $500 coupon to purchase items worth $300, the purchase is successfully made and $200 can be used later. Is that possible ?

hope i am clear with my question.

Thanks a lot for any help