UX in Custom Drop Down List

with a jsfiddle

Whenever I see the custom UIs built with javascript, I always wanted to see the behavior of native UIs. For example, when you use dropdown-like UIs, I’d expect to see the list is opened as soon as you mousedown instead of releasing the mouse. Also, I think the item in the list should be selected when the mouse button is released, rather than as soon as the button is mouse down.

Here’s the jsfiddle that I played around with: http://jsfiddle.net/studiotimo/FvCbh/