title: Prevent the popup window from opening if the check failed
body: <p>I would like to prevent the popup window from opening if the check failed? Is it possible with the following setup? Currently, it opens the popup window with the current page (with error msg) if the check failed.</p>
  
  <pre><code>Link myLink = new Link( "confirm-new-stuff" )
      {
          @Override
          public void onClick()
          {
              if ( Boolean.valueOf( confirmReadDocCheckbox.getValue() ) )
              {
                  confirmationCheckboxFeedback.setVisible( false );
                  setResponsePage( SuccessPage.class, getPageParameters() );
              }
              else
              {
                  confirmationCheckboxFeedback.setVisible( true );
              }
          }
      };
      myLink.setPopupSettings( popupSettings );
      add( myLink );
  </code></pre>