procedure TForm1.Button2Click(Sender: TObject);

   procedure NodoEnBold(node: TTreeNode; OnOff: Boolean);
   var
     tvi: TTVItem;
   begin
     FillChar(tvi, SizeOf(tvi), 0);
     tvi.hItem := node.ItemID;
     tvi.Mask := TVIF_STATE;
     tvi.StateMask := TVIS_BOLD;
     if OnOff then tvi.State := TVIS_BOLD
              else tvi.State := 0;
     TreeView_SetItem(node.Handle, tvi);
   end;


 begin
   {Poner en Negrita el Nodo seleccionado...}
   {Put Bold the selected node of Tv1...}
   NodoEnBold(Tv1.Selected,TRUE);
 end;