Custom Combo/ List box change the background

[PreCoder]

Hi all,
I have been going crazy with this problem, seems so simple. All I want to do is change the graphics on a Combo Box (list box dreamweaver calls it) in HTML from the default system graphics.

Here is what I have:

http://www.firefoxdesign.com.au/test/combo.html

I want all of the combo box to have a background of darkgrey, and I want to replace the arrow that you click on with one I made, and also when the drop down box comes out for the edging to be a orange colour the same as the text rather then black.

I swear I have looked everywhere for this as it would seem simple to change, but to no avail.

Any help is greatly appreciated,
Cheers,
Carl.