private void BtnThem_Click(object sender, EventArgs e)
        {
            FrmChiTietPhieuTamVang frm = new FrmChiTietPhieuTamVang(null);

            frm.Show();
        }
        private void BtnXemChiTiet_Click(object sender, EventArgs e)
        {
            FrmChiTietPhieuTamVang frm = new FrmChiTietPhieuTamVang(phieuTamVangSelected);

            frm.Show();
        }