A couple of updates to earlier posts :
Dan added a comment that he has a similar system for keeping backups on windows. I’ve attached a copy of his example file to this post for anyone want to do the same thing.
David Head, formally of ULearnIT but now the System Engineer at FileMaker Australia, sent me a note about a similar thing he did on his uLearnIT blog. His post is about how you can force checkboxes ( which can be turned off without holding shift ) to behave like radio buttons in that they will only allow one selection at a time.
I’m also going to take a stab at his challenge, and suggest that you could do what he was asking with
RightValues ( Self ; 3 ). Unless there’s a gotcha he knows about that I haven’t seen 🙂
Also note ( as I was reminded by Doug Rowe ) that Self only works with v10 or later and it even had some issues with separation model solutions in 10, so if you don’t have 11, maybe reference the field directly instead.