arr = new Array(9);

Here's an example of how to create a constructor function:

anim1 = new animation("ball1");

where animation is a user-defined function. Here is an example:

function animation(id) {
  this.element = (NS4) ? document[id] : document.all[id].style;
  this.active = 0;
  this.timer = null;
  this.path = null;
  this.num = null;

  this.name = id + "Var";
  eval(this.name + " = this");

  this.animate = animate;
  this.step = step;
  this.show = show;
  this.hide = hide;
  this.left = left;
  this.top = top;
  this.moveTo = moveTo;
  this.slideBy = slideBy;
  this.slideTo = slideTo;
  this.circle = circle;
}

Notice the usage of the this prefix which gives you a reference to the object's father.

Learn more about memory allocation in Column 18, JavaScript Animation, Part I.

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