private void btnEditSector_Click(object sender, EventArgs e)
 {
     int index = lstSegments.SelectedIndex;
     if (index >= 0)
     {
         FormAddSegment form = new FormAddSegment((Sector)lstSegments.SelectedItem);
         if (form.ShowDialog() == DialogResult.OK)
         {
             lstSegments.Items.RemoveAt(index);
             lstSegments.Items.Insert(index, form.Data);
         }
     }
 }
 private void btnAddSector_Click(object sender, EventArgs e)
 {
     FormAddSegment form = new FormAddSegment();
     DialogResult res = form.ShowDialog();
     if (res == System.Windows.Forms.DialogResult.OK)
     {
         lstSegments.Items.Add(form.Data);
     }
 }