private void btnLapHoaDonMoi_Click(object sender, EventArgs e) { i = 0; Tien = 0; txtTongtien.Text = "0"; btnLapHoaDonMoi.Enabled = false; btnThemSP.Enabled = false; pbcheck.Enabled = true; btnIn.Enabled = true; txtMaKH.ReadOnly = false; txtSoHD.Text = HoaDonBanHangBUS.GetIDHoaDon(); txtMaSP.ResetText(); txtTenSP.ResetText(); txtGiamGia.ResetText(); txtGiaBan.ResetText(); txtMaKH.ResetText(); dtkNgayLap.Value = DateTime.Now; dgvDanhSach.Rows.Clear(); }