CSS - stationary div at the top of the page while the rest of the page scrolls.
I'm building a page that will have a navigation bar that spans the top of the page. The page will be 1024px wide, centered in the browser window and there is a background image that will show on both sides of the page for windows that show more than 1024px in width. I want the navigation bar to remain at the top of the browser window regardless of scrolling the page up and down. What needs to be done with the CSS for this to work?