Hmmm.... I would just add a shim to the Prev/Next JS code to populate a hidden field, or look for the proper form elements when posted by those two events, and set the visibility accordingly. Joel D Canfield wrote: >> Why not on post-back change the visibility to what you want >> server side? > > Well, what I want depends entirely on what's been clicked on the > calendar: if it's a date, we *want* the calendar to stay hidden, and > populate the form field. If it's the next/previous link, we don't. > > I just don't know how to differentiate, or even if you can.