Keep random from repeating

I’ve got a random function set up to tell the playhead of my movie to head to random frame lables in a mc (i.e. label1, label2, etc.)

var randLabel:Number = Math.round(Math.random() * 12) + 1;
var label:String = "label"+randLabel;

What I’d like to achieve is to be able to store which frame lable played already so it is not played again until all the frame labels have played.
So say the first label played is “label3”, then that will not be played again until all the other frame labels played.