Conditional fields

Conditional fields

Hi, 

I have a question about creating forms
I'm willig to have an application that gonna contains many froms, one form is going to contain some versions, and in the other form I should display this versions, added in the first form, as a dropdown field. is it possible to do so?

And, I'd like to have conditional fields, for example a field is not shown till another field is well filled 

Kind regards