ActionScript 3.0 :: Scale Container In Another Variable Container?

I need to place an image into a container. The problem is that I will not know the size of the image or the container beforehand, so it all has to be dynamic.this is how I started (have not gotten to stage(or container) changing size yet. No matter what I try, either all the images are the same width, or they are all the same height. If some images are portrait and other landscape, I don't want all the images to be X pixels high. In this variation of the code, all the images turn out the same height, regardless of portrait or landscape.

ActionScript Code:
var ratio:Number = container.width/container.height;//get the ratio, if width is bigger than height then ratio is greater than 1, else ratio is smaller than 1

[code]........