public ActionResult Index(NhaXuatBan nxb, string moTa, HttpPostedFileBase file)
        {
            var tk = Session["TaiKhoan"] as KhachHang;

            if (tk == null)
            {
                return(View("../Login/Index"));
            }
            else
            {
                if (tk.LoaiTK != "Admin")
                {
                    return(View("../Home/Index"));
                }
                else
                {
                    if (Session["UpdateNXB"] == null)
                    {
                        var db = new NhaXuatBanDAO();
                        db.InsertNXB(nxb, moTa, file);
                        Session["ListNXB"] = null;
                        return(RedirectToAction("Reset", "NhaXuatBan", new { area = "Admin" }));
                    }
                    else
                    {
                        var db   = new NhaXuatBanDAO();
                        var nxb1 = Session["UpdateNXB"] as NhaXuatBan;
                        db.UpdateNXB(nxb1.IdNXB, nxb, moTa, file);
                        Session["UpdateNXB"] = null;
                        Session["ListNXB"]   = null;
                        return(RedirectToAction("Reset", "NhaXuatBan", new { area = "Admin" }));
                    }
                }
            }
        }