public void LoadHD()
 {
     try
     {
         dgvHD.DataSource = cnb.ViewKyHopDong("SELECT KyHopDong.MaHD,KyHopDong.TuNgay,KyHopDong.DenNgay,Kyhopdong.NgayKyHD,KyHopDong.DieuKhoan,KyHopDong.MaNV,HopDong.LoaiHopDong,HopDong.KyHan,CongNhan.Ten FROM KyHopDong,HopDong,CongNhan WHERE KyHopDong.MaHD=HopDong.MaHD AND KyHopDong.MaNV=CongNhan.MaNV").ToList();
     }
     catch (Exception p)
     {
         MessageBox.Show(p.ToString());
     }
 }