code: public static String makeIECachingSafeUrl(String url, long unique) {
          if (url.contains("timestamp=")) {
              return url.replaceFirst("(.*)(timestamp=)(.*)([&#].*)", "$1$2" + unique + "$4")
                      .replaceFirst("(.*)(timestamp=)(.*)$", "$1$2" + unique);
          } else {
              return url.contains("?")
                      ? url + "&timestamp=" + unique
                      : url + "?timestamp=" + unique;
          }
      }
docs: Makes new unique URL to avoid IE caching.
  @param url
  @param unique
  @return