Does anyone know where I can find some code to do a mapping effect. I'm not sure if thats the right term but what I'm after is.

I have a scaled down image as a small box. This small image will have MouseEvent.MOVE where it reads the mouse coordinates of that box. Then I have a full scale image in another movieclip masked out with a small viewport area to view part of the full-scale image. When you mouse over the small box image it moves the large image around in the view port.

Sorry I can't find an example when I need one as I know there are plenty online.