Loading/unloading movies with transitions

First post…yea!!
So I’m a new to actionscript and my brain is hurting now. I am working on a website for my wife that “just has to be Flash!” So I’m planning. I want to have an empty movie clip to load external movies into and have them controlled by the nav (this will be the content for subsequent pages). When I unload the previously loaded movie, I want it to fade out (or animate away in some fashion). How do I do that? I’ve been successful at how to load/unload movies in the empty mc, but I don’t know how to make a transition between the loading movies. Does that make sense? Is there a better way to do this? Thanks for any help.