/**
  * @param mapping
  * @param form
  * @param request
  * @param response
  * @return ActionForward
  * @throws Exception
  */
 public ActionForward toggleActiveDns(
     ActionMapping mapping,
     ActionForm form,
     HttpServletRequest request,
     HttpServletResponse response)
     throws Exception {
   WebForwardForm webForwardForm = (WebForwardForm) form;
   if (webForwardForm.isActiveDNS()) {
     webForwardForm.setHostHeader("");
   }
   return mapping.findForward("display");
 }