This is probably a beginner question, but what is the purpose of the hidden field that each question has? Every question has additionally to its regular field a hidden that has the same id (except it starts with java*, probably for javascript (?) ). What is it for?

Yes, it's for Expression manager system.

This input must be set as disable …

Thanks! So when I change a regular input field via javascript, how do I take care of this field? Is it enough to trigger a change event on the corresponding regular input field?

fishfang wrote: Is it enough to trigger a change event on the corresponding regular input field?

It must be enough .

You need only if you have expression system in same page.