Quentin, thanks, but I did it differently. Obviously, I cannot retrieve the initial state as set in Editor, so I defined the fields in code too. But because they are many, I didn’t want to write it out in full. So I dumped all required fields into an array and toggle required-attrib in a loop, depending on status. A lot shorted and as an added bonus, I can check validity the same way: loop thru the array.
Downside is that I have to remember to add a fields also to the array if I add a required field in form.