Code in frame 1 layer 1:

//lotsOfSprites.fla
//Demonstrates creating multiple sprites at run time


i = 0;

theButton.onRelease = function(){
  i++;
  _root.attachMovie("ball", "ball_" + i, 10 + i);
  currentBall = eval("ball_" + i);
  currentBall._x = Math.random() * Stage.width;
  currentBall._y = Math.random() * Stage.height;
  currentBall.index = i;
  trace ("the index is " + currentBall.index);

  currentBall.onRelease = function(){
    output = "last ball clicked...  #" + this.index;
    this.removeMovieClip();
  } // end onRelease
        
} // end theButton