Change the event that causes the popupcontrol to shows the control

I want to use popupcontrol with a textbox, but I want it shows the popup just when the onKeyDown event fires. How can I do it (if it can be done)?You'll want to look at modifying the way PopupControlBehavior.js's this.initialize function attaches its events. You'll probably need to customize the events a little, but it shouldn't require many changes.