void confirmDelete() {

    // Create the window...
    subwindow = new Window("Xoa ??");
    // ...and make it modal
    subwindow.setModal(true);

    // Configure the windws layout; by default a VerticalLayout
    VerticalLayout layout = (VerticalLayout) subwindow.getContent();
    layout.setMargin(true);
    layout.setSpacing(true);

    // Add some content; a label and a close-button
    Label message = new Label("Ban co chac chan muon xoa ?");
    subwindow.addComponent(message);

    Button close =
        new Button(
            "Co",
            new Button.ClickListener() {

              @Override
              public void buttonClick(ClickEvent event) {

                (subwindow.getParent()).removeWindow(subwindow);
              }
            });
    // The components added to the window are actually added to the window's
    // layout; you can use either. Alignments are set using the layout
    layout.addComponent(close);
    layout.setComponentAlignment(close, Alignment.TOP_RIGHT);
  } // end of confirmDelete