Creating order forms with individual orders to show up in one cart

How do I create order forms where all the items that individuals order will show up in one cart.  For example, I'll place an order for one item, go and place an order for the 2nd items and the first items is replaced by the 2nd item in the paypal cart.

Thanks.

Gloria.

Hello Gloria,

Could you explain your requirement a little more so that we can guide you in the right direction. As I check your JotForm, I see only one product with multiple options added on to PayPal products list. 

We will wait for your response.