Hello BattleCat,
There are 2 ways you could solve this. The first would be to use formatting rules that if disagree = True disable the control (on Agree). This would prevent a user from checking both boxes, and would have to uncheck one to check the other.
Option 2 would be to use action rules. On the one that is checked (Agree) set an action that when Agree=True set a fields value (disagree) to false.
Another option would be to use option buttons. Option buttons are a better choice when you want users to only be able to select one entry.
Hope that helps!
Bre
Bre Huston
| Project Manager
Qdabra® Software / InfoPathDev.com / FormsQuo / 877.544.2389 main / 425.318.7843 direct
Business Process Automation for Everyone – Streamline data gathering to
turn process into knowledge.™