Multiple choice in cart variants?

[Fintan]

On my pizza site I have different sizes to choose form and various ingredients which can be added to the basic pizza .

I have added them as cart variant custom fields.
So far so good, but I need them as multiple choice items (either ctrl key or other).

How do I implement this option?

[Fintan]

No one?

I tried this:
http://network.convergenceservices.in/forum/46-virtue-mart/1238-steps-for-adding-attributes--custom-fields-in-virtue-mart-20--to-products.html

but without success.