private void cboTenSanPham_SelectedIndexChanged(object sender, EventArgs e) { try { if (cboTenSanPham.SelectedValue.ToString().Length == 0) return; int khoa = Int32.Parse(cboTenSanPham.SelectedValue.ToString()); ProductNameManager productNameManager = new ProductNameManager(); ProductName productName = productNameManager.GetById(khoa, true); cboLoaiSanPham.SelectedValue = productName.CategoryIdLookup.ID; cboNhaSanXuat.SelectedValue = productName.ManIdLookup.ID; ManufacturerManager manufacturerManager = new ManufacturerManager(); Manufacturer man = manufacturerManager.GetById(productName.ManIdLookup.ID, true); cboNguonGoc.SelectedValue = man.CountryIdLookup.ID; } catch (Exception ex) {} }