foreach (ListViewItem item in LW.Items)
                    {
                        if (item.Content.Equals("Adobe Photoshop"))
                        {
                            MessageBox.Show("Ошибка");
                        }
                        else
                        {
                            Product AdobePH = new Product { Title = "Adobe Photoshop", Number = 1, NumPrice = 10, Price = 20, Placement = "в наличии" };
                            ((ArrayList)LW.Resources["Product1"]).Add(AdobePH);
                        }
                    }