code: public String addURLParam(String strOldURL, String strParam, String strData)
      {
          return Utility.addURLParam(strOldURL, strParam, strData);
      }
docs: Get the command string that will restore this screen.
  Override in Screen, GridScreen, MenuScreen.
  @param strOldURL The URL to add this param to.
  @param strParam The new param.
  @param strData The new data for this param.
  @return The new URL.
  @see Utility.addURLParam.