onExitFrame method exist or similar?

In the article kirupa wrote called, “Photo Gallery Using XML and Flash” link he had the following function:

this.onEnterFrame = function() { 
filesize = picture.getBytesTotal(); 
loaded = picture.getBytesLoaded(); 
preloader._visible = true; 
if (loaded != filesize) { 
preloader.preload_bar._xscale = 100*loaded/filesize; 
} else { 
preloader._visible = false; 
if (picture._alpha<100) { 
picture._alpha += 10; 

Is there a similar method that we can reverse transition so the image fades away as the new image fades in and not see the preloader?