add_button.clicked.connect( () => {
                pop = new PopOver ();
                var pop_vbox = (Gtk.VBox) pop.get_content_area();
                pop_vbox.add(label_pop);
                pop_vbox.add(this.entry);
                pop_vbox.add(this.date_picker);
//                pop_hbox.add(label_notes);
//                pop_hbox.add(this.comment);
                pop_vbox.add(add_pop) ;
                pop.move_to_widget(add_button);
                pop.set_parent_pop(this.window);
                pop.show_all();
                pop.run();
                pop.destroy();
            });