I have 2 list boxes A and B, both are unrelated. Now is there an option if I select A then I cannot select B or vice versa. The only way I could do that is press clear and then select B.
You could put a conditional show on each (Properties -> Layout -> Show -> Conditional):
getselectedcount(A)=0 // on B getselectedcount(B)=0 // on A
So initially, both would show. As soon as you selected from one, the other would disappear. Clear, and they'll both show again.
Or you could write a macro that triggers onselect of each field. The macro would check if anything is selected in the other field, and clear the most recent selection if so. I could see that leading to user frustration, though, unless you also put up a message of some sort.
