This is a demonstration of JWee's mouseenter and mouseleave event handlers.

Note how little boxes inside the big boxes do not cause repeat mouse over events (the zooming) to their parents. You can see how you can "mouseenter" into a 2nd level box while the parent box remains active (green border). Using standard mouseover events this is not possible, since mouseout would trigger on the parent box even though the actual mouse position still is within it. This works in Internet Explorer and Firefox as well. Refresh the page to get a different arrangement of boxes below.