//-------------------------------------------------------------------------------------
 // this message handler gets called when the user checks/unchecks an item the combo box
 //----------------------------------------------------------------------------------------
 private void cmboSizes_CheckStateChanged(object sender, EventArgs e)
 {
     if (sender is Cutting.CheckComboBoxItem && FormLoaded)
     {
         Cutting.CheckComboBoxItem item = (Cutting.CheckComboBoxItem)sender;
         if (item.CheckState)
         {
             QueryParms.Sizes.Add(repo.LoadSize(item._Pk));
         }
         else
         {
             var value = QueryParms.Sizes.Find(it => it.SI_id == item._Pk);
             if (value != null)
             {
                 QueryParms.Sizes.Remove(value);
             }
         }
     }
 }