AS2: randomizing location of movieclips

I have 7 movieclips that form a line down the stage like so:

Movieclip 1
Movieclip 2
Movieclip 3

I need it so that when a button is pressed is randomizes the order in which they are shown for example it could be:

Movieclip 2
Movieclip 3
Movieclip 1

Any help would be great thanks :yoda: