code: public Object doFilter(Object obj, Method method, Object[] params, AjaxFilterChain chain) throws Exception
      {
          if (System.currentTimeMillis() % 2 == 1)
          {
              return chain.doFilter(obj, method, params);
          }
          else
          {
              throw new SecurityException("Wrong time. Try again later");
          }
      }
docs: /* (non-Javadoc)
  @see uk.ltd.getahead.dwr.AjaxFilter#doFilter(java.lang.Object, java.lang.reflect.Method, java.lang.Object[], uk.ltd.getahead.dwr.AjaxFilterChain)