I'm using FM Pro 10.0 on Leopard. I've created a simple staff in/out board for the receptionist. Beside the employee name I have a check box field. The choices in the value list are: In, Out. Pretty simple. I can't get the check box to force only one check. Right now both boxes can be checked, or only one checked or none checked. I want to restrict it to either In or Out. If they check In then Out gets deselected and vice versa. This should be simple, but I can't see how to make this work. Any suggestions? I'm pretty much a FM newbie, which is probably why I'm not seeing the solution.