Resize window for pictures

Hi, I´ve searched on this subjcet but didn´t find anything.

This is the deal.
The user chooses a pictures froma menu, and that picture is loaded on the main movie, on a “square”, like a photo frame, but since the images are not all the same size, I´d like to make the square behind them to adjust itself to the size of the pictures as they are loaded.

Thanks

might wanna stick this in the Flash MX Help section (assuming it’s MX)