Word 2002 form formating question

Hello everyone

I am making a form in Word 2002 and in it I have check boxes that represent selectable options. Lets say I have box A and Box B. Box A and B are opposed to each other, meaning you can select A or B but not both and I don’t want the user to be able to select them both.

How can I unselect box A if its selected and the user clicks on box B and Vise-versa.

Thank you in advance.

TCB