I was following a tutorial and input the AS code :
_root.onEnterFrame = function(){
if(_root._xmouse<50){
imgBar.prevFrame();
}
}
and im getting this : ReferenceError: Error #1065: Variable _root is not defined.
at Sliding_fla::MainTimeline/Sliding_fla::frame1()
I’m very new to AS and flash so if you’re willing to help, please be patient… 
Thanks.