Is this AS3?

programming flash
1

Hi forum
I’m doing a small project for a client. I have been given an ‘AS2’ FLA containing this code:

stop();
addEventListener(Event.ENTER_FRAME, loading);

function loading(event:Event) 
{
   var bytestotal = stage.loaderInfo.bytesTotal;
   var bytesloaded = stage.loaderInfo.bytesLoaded;
   var sclbar = Math.round(bytesloaded*100/bytestotal);
   loader_mc.LoadingText.text = sclbar + "%";
   loader_mc.gotoAndPlay(sclbar);
   if (bytesloaded >= bytestotal) 
   {
      gotoAndPlay(2);
      removeEventListener(Event.ENTER_FRAME, loading);
   }
}

Can anyone confirm if this is AS2 or AS3 please?

I ask because it won’t compile, stating:

"Scene=preloader, layer=Layer 1, frame=1, Line 4    The class or interface 'Event' could not be loaded."

Thanks