public JsonResult LoadThongTinHocSinh(int?HocSinh)
 {
     try
     {
         var TrungTam = Task.Run(() => db.APAX_GetTrungTamBayUserName(User.Identity.Name).FirstOrDefault()).Result;
         var model    = db.TH_HOSOKHACHHANG.FirstOrDefault(it => it.A_HOSOKHACHHANG == HocSinh);
         model.ID_TRUNGTAM = TrungTam.TrungTam;
         model.MATRUNGTAM  = TrungTam.MA_DVCS;
         if (model != null)
         {
             return(Json(model, JsonRequestBehavior.AllowGet));
         }
         else
         {
             return(Json(null, JsonRequestBehavior.AllowGet));
         }
     }
     catch
     {
         return(Json(null, JsonRequestBehavior.AllowGet));
     }
 }