Several uploads and at least one mandatory

Hello,

I can see that there are a lot of posts about the following that I want solved but cannot find any which explains exactly what I want.

What I want:

I want to add digital scrapbooking services to my webshop. This means that customers browse through my shop and look for templates that they like.
When they select the preffered template I want them to be able to upload "SEVERAL", not just one, images and I want this to be mandatory before they can hit the ADD TO CART button and add it to the shopping cart.

How would I go about to do this?

I have been testing things I read on in other posts but I can only get the upload attribute to add ONE image and it is not mandatory. My test product will allow me to buy the product wehter I upload a file or not and I cannot add more that one image.

For the record I am using zen cart version 1.3.9.a at the moment of writing.

Would appreciate any help here:smile:

Kind regards,

Terje