void load_data()
{
PhieuNhapDTO pn = new PhieuNhapDTO();
pn.ma_phieu_nhap = txtMaPN.Text;
dgvSanPham.DataSource = SanPhamBUS.Load_DSSP();
cbxLSP.DataSource = cbxLoaiSP.DataSource = LoaiSanPhamBUS.Load_DSLSP();
dgvChitietPN.DataSource = PhieuNhapBUS.Load_DSMaPN(pnh);
cbxLSP.DisplayMember = cbxLoaiSP.DisplayMember = "ten_loai_sp";
cbxLSP.ValueMember = cbxLoaiSP.ValueMember = "ma_loai";
cbxNVLPN.DataSource = NhanVienBUS.GetDSNV();
cbxNVLPN.DisplayMember = "ten_nv";
cbxNVLPN.ValueMember = "ma_nv";
cbxNCC.DataSource = NhaCCBUS.Load_DSNCC();
cbxNCC.DisplayMember = "ten_ncc";
cbxNCC.ValueMember = "ma_ncc";
groupBox2.Enabled = false;
}