Transition between MC's

Can somebody, please, come up with something for this. I’ve tried different variations, but nothing works.

For example: I have a movie clip playing on a certain level. I have buttons on the stage that load different movie clips on that level. So far it’s very easy. loadMovieNum (“name.swf”, #);

The thing is I don’t want a new MC just to replace an old one. I want an old one to have a nice go away transition and only then a new movie clip will load.

How to do that, since different movie clips are going to be on that level at different times?