attachMovie fade in/out - Anyone done this?

Hello!!

I’m trying to work out the easiest way to make this possible.

I have a series of thumbnail images, each one of them actions attachMovie - bringing it’s own movieClip to my stage.

When a different thumbnail/button is clicked, I want the currently playing movieClip to fade out while the new mclip fades in.

How do I do this?

With an array?

Please help.