When you embed the swf in the html set the width and height parameters to 100%. This will make your swf scale to the size of the browser. Obviously, if its not all vector, bitmap images will look bad. You may want some things not to scale but stay right, stay left, stay bottom, or center etc. This is actually pretty easy. Do a search for "flash fluid layout" sometimes called "liquid layout" there are tons of tutorials on this subject out there. Here's one to get you started.