code: private VerticalLayout getContent() {
  
          String message;
  
          if (m_sitesToDelete.size() == 1) {
              message = CmsVaadinUtils.getMessageText(
                  Messages.GUI_SITE_CONFIRM_DELETE_SITE_1,
                  m_sitesToDelete.get(0).getTitle());
          } else {
              message = "";
              for (CmsSite site : m_sitesToDelete) {
                  if (message.length() > 0) {
                      message += ", ";
                  }
                  message += site.getTitle();
              }
              message = CmsVaadinUtils.getMessageText(Messages.GUI_SITE_CONFIRM_DELETE_SITES_1, message);
          }
  
          VerticalLayout layout = new VerticalLayout();
  
          m_deleteResources = new CheckBox();
          m_deleteResources.setCaption(CmsVaadinUtils.getMessageText(Messages.GUI_SITE_DELETE_RESOURCES_0));
          m_deleteResources.setDescription(CmsVaadinUtils.getMessageText(Messages.GUI_SITE_DELETE_RESOURCES_HELP_0));
  
          layout.addComponent(m_deleteResources);
  
          Label label = new Label();
          label.setContentMode(ContentMode.HTML);
          label.setValue(message);
  
          layout.addComponent(label);
          return layout;
      }
docs: Creates content of dialog containing CheckBox if resources should be deleted and a messages.<p>
  
  @return vertical layout component.