Add multi products with one button

I want add multi products with one add to cart button in Virtuemart 2 and joomla 2.5 For the same product I have 3 type of packaging (I use 3 different products with our sku). For example: Product 1: packaging small 100 pieces Euro 10 (sku 57371002w) packaging small 1000 pieces Euro 80 (sku 57371002x) packaging small 10000 pieces Euro 700 (sku 57371002y) Product 2: packaging small 200 pieces Euro 5 (sku 55882015w) packaging small 2000 pieces Euro 40 (sku 55882015x) packaging small 5000 pieces Euro 85 (sku 55882015y) The first part of sku is equal for the same product, change the last caratter for the packaging. Now if a custumer needs 31200 pieces of product 1, he must add 3 packaing of 10000 pieces, 1 packaging of 1000 pieces and 2 packaging of 100 pieces with 3 click. I wil want with only one click.