stage.addEventListener(Event.ENTER_FRAME, onFrameLoop);
 
function onFrameLoop(evt : Event) : void {
   if ( redCircle.hitTestObject(blueGray) ) {
       hit_txt.text = "COLLISION!    COLLISION!     COLLISION!";
   } else {
       hit_txt.text = "redCircle.hitTestObject(blueGray) is FALSE";
   }
}