VM Custom fields

Hi,
I'm trying the Storebox template.

For the choice of sizes, I need two indipendent dropboxes in the same product page (men's sizes and women's sizes), giving the choice to select only one box and to get only this one into cart. Do you have any idea how this is possible? Do I need two cart buttons? And if so how?

Thanks,
Jochen

Perhaps it would be better to ask on VM forum, as our template only makes changes to the way items are shown in VM views, not how VM works in its basis.