private void btnSpoorSectorBlokkeren_Click(object sender, EventArgs e) { if (cbSpoorSectorblokkeren.SelectedItem != null) { int spoor = Convert.ToInt32(cbSpoorSectorblokkeren.SelectedItem.ToString()); MessageBox.Show(bc.ToggleSpoor(bc.GetSpoorByNummer(spoor))); } else { MessageBox.Show(errorselect); } }