Adjustable Quantity that allows a POP UP notification if Zero is not changed to an amount.

When the adjustable quantity is auto set to 0 on an order form, have a pop up that tells people they have not selected an item when they click "submit" and all items are still at 0.

The way it is now if I set up a conditional trigger that they can only be put into the campaign if they buy 1 or more...there is still no way for them to rebuy unless I send them an email or call them.  Not very useful and a lot of extra work.

We have multiple options on an order form so having it set to Adjustable Quantity of zero is the best practice. So it seems weird that we allow them to purchase.  HELP. 

Thank you for your attention to the matter!