form design - pls give a hand

I am using excel to design a simple form.

I can't make the form control buttun to work. Can anybody help please?

Excel - Developer - insert - form control buton (I used the circle for the choice). I can click it and it turns on, but I can't turn it off by clicking it again. I have to use the right button on the mouse and choose "uncheck".

any ideas?

thanks!