Need help for resizable movieclip

Hi, please, could someone help me?

I need to divide my stage into 2 movieclip. One movieclip, the upper one, will occupied ¾ of the whole screen, and the other one, the down one, will occupied the rest of screen.

They will be resizable, I mean, they will adapt to screen resize.

In the upper movieclip, I need to load a series of images (high resolution), smoothly, but they will adapt at any screen resolution.

I use Actionscript 2.

I attach a sample image.

Please, could someone help me? Thanks…