I am developing an add-on with two options in my option group. Both options are simple text entry boxes. I am doing validation on both options when they are saved, but the first option must be set before the second option can be validated. If no options are currently set and I enter data for both options at the same time and then save, the validation for the second option fails because there is no data available from the first option yet (or is there?). I think from a UI perspective, the best way around this would be to have the second option disabled until the first option has been successfully set and validated (saved). Only then would the second option become available to edit and validation would work fine because the first option is already set and available for use in the validation mechanism. What's the best way to do disable an option until another option has been set? I've looked through all of the core admin options, but the examples I find there seem to use a bit too much magic to understand without help.