f8 - added a preloader now as animation not working

1

Any idea why this wouldn’t work once a preloader is added to scene before content?
this.onLoad = function() {
a = 1;
//duration = 1;
//Use a fractional number to
//cut the duration:
duration = 0.92;
maxang = 30;
speed = 1;
}
this.onEnterFrame = function() {
setProperty(_root.content.chandelier, _rotation, (((Math.sin (speeda))(Math.pow (duration, a ))))*maxang);
a = a+0.1;
}