There's nothing wrong with you. It should work. Per the Designer help
"You can use this event to perform actions as a direct response to a
form filler clicking a button, or selecting a radio button or check box
on a form. For example, you can use the mouseUp event for a check box to
hide and show a field on the form. This event is conceptually similar to
the click event and has a similar purpose."Validate there is not another
error causing the behaviour. If you have Acrobat installed on the same...