Error message in Action Script for volume slider

I'm trying to follow a tutorial on creating a volume slider in Flash, and I'm getting an error message in the first function. The tutorial shows two slightly different syntaxes for the function, so I've tried both and they both produce error messages. Here's the code I've got, and below is an image of the error message.


slider_mc.onPress = function () {
      this.startDrag(false,
                        _root.groove_mc._x,
                        _root.groove_mc._y - 100,
                        _root.groove_mc._x,
                        _root.groove_mc._y;     //this is line 6 that gets the error message
};

slider_mc.onRelease = function () {
      stopDrag();
};

Thanks,

JohnStart Free Trial