private void CLB_items_ItemCheck(object sender, ItemCheckEventArgs e)
 {
     if (e.Index == 0)
     {
         if (CLB_items.GetItemChecked(0))
         {
             IEnumerator myEnumerator;
             myEnumerator = CLB_items.CheckedIndices.GetEnumerator(); int y;
             myEnumerator.MoveNext();
             while (myEnumerator.MoveNext() != false)
             {
                 y = (int)myEnumerator.Current;
                 CLB_items.SetItemChecked(y, false);
             }
             myEnumerator.Reset();
             CLB_items.SetItemChecked(0, true);
         }
         else if (CLB_items.GetItemChecked(0) == false)
         {
             for (int i = 1; i < CLB_items.Items.Count; i++)
             {
                 CLB_items.SetItemChecked(i, true);
             }
             CLB_items.SetItemChecked(0, false);
         }
     }
 }
 public CLB_AlternativesToSelect()
 {
     InitializeComponent();
     CLB_items.SetItemChecked(0, true);
     //this.CLB_items.Items.Clear ();
 }