protected void deselect2_Click(object sender, EventArgs e)
 {
     if (lstExcluded.SelectedItem != null)
     {
         //need to reverse the order - find the issue in case of removing the items from index 0
         var desc = from j in lstExcluded.GetSelectedIndices().ToList()
                    orderby j descending
                    select j;
         foreach (int i in desc)
         {
             ExcludedGroup.RemoveAt(i);
         }
         SetAvailableData();
     }
     SetButtons();
 }