setInterval not working as expected

programming flash
1

I used setInterval to fade the main sequence of my page. It works, but for some reason no matter what I change setInterval to, it does it at the same speed of 30 frames per second. So if it has to set the Alpha level from 100% to 0% it will take 3.3 seconds. You can see it here: Http://www.dhicompany.com. Does anyone know why this is or how to fix it?

stop();
function fadeOut(){
_root.loaderClip._alpha–;
_root.barLoad1._alpha–;
_root.barLoad2._alpha–;
updateAfterEvent();
if(_root.barLoad2._alpha<=0){
clearInterval(timer);
_root.gotoAndPlay(“startTwo”);
}
}
timer = setInterval(fadeOut,10);