Related fields in registration

[maxi1973]

Hello everybody, i have a question for expert users:
i need, in registration the field "category" have to appear only if a previous checkbox field have as value "company"; otherwise if i choose in the checkbox "private" need the field "private" to appear. Is it possible do this trick?
Thanks a lot in advance to anyone can help me resolving also with Javascript (or any other possible solution )

[John2400]

Might look or ask here

http://extensions.virtuemart.net/products/breezing-forms-custom-fields-plugin-detail

[maxi1973]

Maybe it helps in product customizations but not in users registration using virtuemart standard registration form.
Is there any function i haven't seen? or a demo site to try registration with custom fields?