How to control scaling maximum size

I’d like to control the maximum scaling of a move embedded in a web page. Using the publish settings of 100% and scaling set to show all, the movie resizes up and down just great, but I don’t want it displaying any larger than 1020 pixels wide. If it scales up beyond that the images start to break up. Hopefully there is a simple html based method, rather than the action script event listener resize with if then else loops.
Thanks, Charlie