public ActionResult Index(string dm)
 {
     if (Assembly.GetExecutingAssembly().GetTypes()
         .Select(type => type.Name).ToList()
         .Contains(String.Format("{0}Controller", dm)))
     {
         return(RedirectToAction("Index", dm, new { dm = dm }));
     }
     ViewBag.DanhMuc = dm;
     return(PartialView(db.loadDanhMuc(dm)));
 }