private void btnNhapIn_Click(object sender, EventArgs e)
 {
     btnNhap.PerformClick();
     if (isValid)
     {
         FrmInPhieu f = new FrmInPhieu(khachLe);
        // f.ShowDialog();
     }
 }
 public static CODE_RESULT_RETURN InPhieuCoCapNhat(HistoryHoiVien hs, bool isGYM)
 {
     try
     {
         FrmInPhieu f = new FrmInPhieu(hs, isGYM);
         using (var db = DBContext.GetContext()) {
             var oldHS = db.HistoryHoiVien.Find(hs.ThoiGian);
             if (isGYM)
             {
                 oldHS.IsDaInGYM = true;
             }
             else {
                 oldHS.IsDaInSauna = true;
             }
             db.SaveChanges();
             return CODE_RESULT_RETURN.ThanhCong;
         }
     }
     catch (Exception ex) {
         return CODE_RESULT_RETURN.ThatBai;
     }
 }
        void inPhieu(bool isGYM)
        {
            if (dgrDangKy.SelectedRows.Count > 0)
            {
                var hv = (HoiVien)dgrDangKy.SelectedRows[0].DataBoundItem;
                if (isGYM && hv.NgayHetHanGYM.Date <= DateTime.Now.Date) {
                    DialogUtils.ShowMessage("Thẻ này đã hết hạn GYM");
                    return;
                }
                else if (!isGYM && hv.NgayHetHanSauNa.Date <= DateTime.Now.Date)
                {
                    DialogUtils.ShowMessage("Thẻ này đã hết hạn Sauna");
                    return;
                }
                HistoryHoiVien hs = new HistoryHoiVien() {

                };
                FrmInPhieu f = new FrmInPhieu(hv, isGYM);
                //f.ShowDialog();
            }
        }