referencing 2 variable objects on exit event

I have a drop down question with a yes or no value. If yes, I make a Yes subform visible and reference a yes variable object on the exit. Which works fine independently. If no, I do the same; I make the No sf visible and reference the no variable object. That works fine independently as well. But when both variables are in the script of the dropdown together, they both stop working. Why is this? I have found that referencing my variables only work in the exit event. Should I move the Yes to another script event? It doesn't work in most script events. Please help!