public void cargarListaComprobantes(){
        try{                                        
            r_con.Connection();
            ResultSet rs=r_con.Consultar("select * from tipo_comprobante");
            DefaultListModel modelo = new DefaultListModel();
            while(rs.next()){       
                String cadena=rs.getString(1)+" - "+rs.getString(2);
                cadena=validar.soloPrimerMayus(cadena);
                modelo.addElement(cadena);        
            }
            listaComprobantes.setModel(modelo);
            
            
            // ##################### Multiple seleccion ####################
            // me permite seleccionar varios elementos dentro de la lista
            
            listaComprobantes.setSelectionModel(new DefaultListSelectionModel() {
            private int i0 = -1;
            private int i1 = -1;
            public void setSelectionInterval(int index0, int index1) {
                if(i0 == index0 && i1 == index1){
                    if(getValueIsAdjusting()){
                         setValueIsAdjusting(false);
                         setSelection(index0, index1);
                    }
                }else{
                    i0 = index0;
                    i1 = index1;
                    setValueIsAdjusting(false);
                    setSelection(index0, index1);
                }
            }
            private void setSelection(int index0, int index1){
                if(super.isSelectedIndex(index0)) {
                    super.removeSelectionInterval(index0, index1);
                }else {
                    super.addSelectionInterval(index0, index1);
                }
            }
        });
            
   //    ############################################################
            
        } catch (SQLException ex) {
            Logger.getLogger(IGUI_Asignar_Pto_Venta_Comprobante.class.getName()).log(Level.SEVERE, null, ex);
        } finally {            
            r_con.cierraConexion();
        }
    }