Combining use of Check Box and Option Button
 

Hi there,

I am trying to create an Option Button which is dependant on the other 3
Check Boxes. For example, check box 1 = "campaign in Canada", check box 2
="campaign in US", check box 3 = "campaign in Mexico". And the option button
1 = "don't bother to campaign".

If any of the 3 check boxes are selected then the option button should be
automatically unselected. Also, if non of the check boxes are selected then
option button should be automatically selected. I am almost able to do this
with if statements on linked cells.

But when some of the check boxes are selected I still have the option of
selecting the option button, which deletes my formula ... or in other words,
selecting the option button doesn't make all the check boxes unchecked.

Any help?