private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {


            //ilosc
            using (SqlConnection con = new SqlConnection(polaczenieBaza))
            {
                con.Open();
                try
                {
                    string Sql = "select m.ilosc from produkt p join magazyn m on p.idProdukt = m.idProduktu where p.nazwaProduktu ='" + comboBox1.ToString() +"'";
                    using (SqlCommand cmd = new SqlCommand(Sql, con))

                    {
                        result1 = ((int)cmd.ExecuteScalar());
                        label3.Text = result1.ToString();
                    }

                }

                catch (Exception ex)
                {
                    MessageBox.Show(ex.ToString());
                }

            }
        }