Reset a form on change of Group

Hello, I have a form that is divided into 3 groups.
I use the same elements across all the groups, but I would like to switch between the groups in such a way that the form is reset for every group.

It is a Photography pricing form selling portraits:

[Traditional Portraits]
[Family Portraits]
[Creative Portraits]

Select Print Type   (dropdown)
¬ Canvas
¬ Poster
¬ Block Mount

SHOW this field if  ALL  of the following match:
[Select Print Type] is [Canvas]
Choose your Size   (dropdown)
¬ A4 - $10
¬ A3 - $20
¬ A2 - $30

I guess I am just trying to find the best way to do this, - at current it works great, but the form will remain prepopulated if I change it and then move to the next form.
Thank you very much for your advice. you can see the form live here: http://flashpoets.com/photography-service/ Then Click Portrait photography.