Silhouette Preloader

I want to do a preloader where I can put in an image's silhouette and, instead of a progress bar, show the "real" image in place of the silhouette image, bottoms up. Make sense? I've seen lots of things for preloaders, but how would I go about this? I can't just have the image slide up - it wouldn't look right.

Hi,

Use a mask. Either manipulate the height property or the _y position of the mask to correspond to percent loaded and reveal the image as the mask slides into place.