code: void startValidation() {
  
          m_oldReport.setVisible(false);
          m_threadReport.removeAllComponents();
          CmsExternalLinksValidatorThread thread = new CmsExternalLinksValidatorThread(
              A_CmsUI.getCmsObject(),
              new Runnable() {
  
                  public void run() {
  
                      enableButton();
                  }
  
              });
          thread.start();
          CmsReportWidget reportWidget = new CmsReportWidget(thread);
          reportWidget.setHeight("500px");
          m_threadReport.addComponent(reportWidget);
          m_exec.setEnabled(false);
      }
docs: Starts the validation.<p>