private void btnBrisiKupca_Click(object sender, EventArgs e) { foreach (Control c in tabKupac.Controls) { if (c is TextBox && String.IsNullOrEmpty((c as TextBox).Text)) { MessageBox.Show("Niste izabrali nijednog kupca!"); return; } } admin.ListaKupaca = admin.ObrisiKupca(new Kupac(int.Parse(txtIdKupca.Text), txtIme.Text, txtPrezime.Text, txtJMBG.Text, txtTelefon.Text, dtDatumRod.Value, txtKorisnickoIme.Text, txtLozinka.Text)); foreach (Control c in tabKupac.Controls) { if (c is TextBox) { c.Text = ""; } } lstKupci.Items.Clear(); foreach (Kupac kup in admin.ListaKupaca) { lstKupci.Items.Add(kup.ToString()); } MessageBox.Show("Uspesno obrisano!"); }