or you could create a flash interface, and use the graphics namespace to create a interface, that always monitors the resize event, and adjusts the size of your interface.
like what I did with
www.viadrupsteen.nl
the white bars resize depending on the window size, while the buttons, tabs remain the same. The navigationmap gets fancy scroll handlers if your screen width is smaller then the map width (although in this tour the map is heigh instead of wide, I havent made a height check yet).