code: function(target, value, tween) {
  				this._wdw = (target === _window);
  				this._target = target;
  				this._tween = tween;
  				if (typeof(value) !== "object") {
  					value = {y:value}; //if we don't receive an object as the parameter, assume the user intends "y".
  				}
  				this.vars = value;
  				this._autoKill = (value.autoKill !== false);
  				this.x = this.xPrev = this.getX();
  				this.y = this.yPrev = this.getY();
  				if (value.x != null) {
  					this._addTween(this, "x", this.x, (value.x === "max") ? _max(target, "x") : value.x, "scrollTo_x", true);
  					this._overwriteProps.push("scrollTo_x");
  				} else {
  					this.skipX = true;
  				}
  				if (value.y != null) {
  					this._addTween(this, "y", this.y, (value.y === "max") ? _max(target, "y") : value.y, "scrollTo_y", true);
  					this._overwriteProps.push("scrollTo_y");
  				} else {
  					this.skipY = true;
  				}
  				return true;
  			}
docs: called when the tween renders for the first time. This is where initial values should be recorded and any setup routines should run.