How to test that a field is not empty not using the button action method?

Hello,

I have a standard form with submit button.

Most of the input fields can't be empty on submit.

Is there any way in DynPro to test that these input fields are not empty other than checking each context at the action method handler of the button? I would like that the user will be notified of these fields before submiting the form (Like in Javascript...).

Roy