Field #1 is a number field with a drop-down list calling upon a dynamically created value list using values from another table.

Field #2 is a number field with a pop-up menu calling upon a dynamically created value list using values from another table that are related to the value in field #1.

The proper workflow is: The user makes a selection from the drop-down list in Field #1, then makes a selection from the pop-up menu in Field #2. When this happens everything works great.

The problem is, the user can make a section in Field #1, then make a selection in Field #2, and then go back and change the selection in Field #1. When this happens it mildly screws up a few relationships which I'm naturally trying to avoid.

Is there any way to tell FileMaker "whenever the value in Field #1 changes from what it was, erase the value in Field #2"? The workaround I have now is a button that erases Field #2, but I want something that's automatic and doesn't depend on the user.

LOL, so soon? See if this helps:

http://www.fmforums.com/forum/showpost.php?post/195641/

Yeah, I know. : What you gave me yesterday worked well; that's not the problem. I'm now trying to add a layer of idiot-proofing to my database so that Bad Things don't happen.

Thanks for the link; I'll take a look.