How to find event listeners on a DOM node in JavaScript or in debugging?

Question

I have a page where some event listeners are attached to input boxes and select boxes. Is there a way to find out which event listeners are observing a particular DOM node and for what event?

Events are attached using:

1. Prototype's Event.observe;
2. DOM's addEventListener;
3. As element attribute element.onclick.

Answer

If you just need to inspect what's happening on a page, you might try the Visual Event bookmarklet.

Update : Visual Event 2 available.