i have a form with a number of checkboxes (let’s call them A, B, and C).

I am looking for a script which will enable a fourth checkbox (checkbox D) to be turned on if any and all of checkboxes A, B, or C are checked. And also turned back off if checkboxes A, B, or C are subsequently unchecked.

seems to be a deceptively simple task.

thank you so much in advance.