private void btnThem_Click(object sender, EventArgs e) { int MaNV = Convert.ToInt32(txtMaNV.Text); int MaNCC = Convert.ToInt32(txtNCC.Text); string NgayNhap = dtpNgayNhap.Value.ToString("MM/dd/yyyy"); PhieuNhap phieunhap = new PhieuNhap(-1, NgayNhap, MaNV, MaNCC); PhieuNhapBLL.PhieuNhap_Insert(phieunhap); LoadPhieuNhap(); }