void recycleDisplayCache(int depth, DisplayObject displayObj){
displayObj.view.visible = false;
Movie movie = displayObj as Movie;
if(movie!=null)
movie.StopRecursive();
List<DisplayObject> caches = _depth_displayCaches[depth];
if(caches==null){
caches = new List<DisplayObject>(2);
_depth_displayCaches[depth] = caches;
}
caches.Add(displayObj);
}