public ActionResult Delete(int id)
 {
     try
     {
         Zalo zalo = new Zalo();
         zalo.DeleteById(id, db);
         Transaction con = db.Transactions.Where(x => x.ID == id).FirstOrDefault <Transaction>();
         db.Transactions.Remove(con);
         db.SaveChanges();
         return(Json(new { success = true, message = "Xóa giao dịch thành công!" }, JsonRequestBehavior.AllowGet));
     }
     catch (Exception ex)
     {
         help.LogError(ex);
         return(Json(new { success = false, message = "Lỗi xóa giao dịch!" }, JsonRequestBehavior.AllowGet));
     }
 }