Change size of SWF/FLA

I’m wondering whether it’s possible to change the size of a flash application at runtime?

I know I can scale the SWF with HTML/JavaScript, but I’m not talking about scaling here. I want to change the actual size, not just enlarge it visually. Let’s say my SWF is 400x300 pixels. At runtime, I want to change it to 500x400. All the elements inside the SWF (buttons or whatever) should remain the same size. It’s the Stage itself that should change.

Is this possible, and if so; how do I do it?