private void comboTip_SelectedIndexChanged(object sender, EventArgs e) { Automobil auto = new Automobil(); if (comboModel.SelectedIndex != 0 && comboTip.SelectedIndex != 0) { int modelTipID = auto.DohvatiModelTipID((int)comboModel.SelectedValue, (int)comboTip.SelectedValue); label4.Text = modelTipID.ToString(); } else { label4.Text = "-1"; } }