Thanks for your help with this, Ray! I'll keep you posted.
By the way, there is a funny thing with the UI for those server behaviors. If I change the trigger selection, and then click on the OK button, it always selects the first element in the list (any form post, I think). To make my selection take, I have to a) select it, and b) click on some other field before clicking on the OK button. I assume you already have that in the queue, though....