Custom Scrollbar

I currently have a sidebar and text that I want to scroll down in the text box, rather than extending the site vertically. However the scrollbar is ugly.

I know that CSS can be applied to flash to format text, so would it be possible to manipulate the look of the scrollbar? Or should I create my own arrows to move text up and down?

I just figured that if the CSS will work, it would be quicker, as I havent tried making my own.