To do fade-out before closing clip and that then charge another

I have a web that is charged in different levels. It with himself with a menu and with the codigo in each boton if:

on (release)
{loadMovieNum (“level.swf”,40);

To there all well. All the clips are charged al start with a fade-in obtained with the alpha of the layer. What I want to manage to is that al to pressure any boton so that be charged any clip, the clip that this in that moment in action (be which be and without the boton determine which is) disappear doing a fade-out before charging the corresponding one al boton press. If it serves of aid to should to tell you that all the clips in which interests me to put that effect are in the same layer and that the one that this running in that alone moment the visitor determines it with its sailed.

The clip that this loaded one can be one any of the 6 that can do it. Then I need a general order so that any of them closed without specifying which of them.