swfresize is a small bit of JavaScript that helps a “full-screen” Flash application be as large as possible and still maintain it's aspect ratio, and keep everything within the viewable area of the browser.
Features:
Allow SWF to be 100% within the browser window
Force minimum width for SWF
Force a certain amount of the SWF height to always be “above the fold” (perfect for SWFs that are taller than they are wider)
Keeps the aspect ratio of original SWF file
Great for “full-screen” Flash applications
Works with SWFObject
Only takes two lines of code to implement