@Override
   public void run()
   {
      keep_running = true;
      readStringFromFile();
      last_timestamp = fl_file.lastModified();

      while(keep_running)
      {
         long cur_timestamp = fl_file.lastModified();

         if(last_timestamp != cur_timestamp)
         {
            readStringFromFile();
            last_timestamp = cur_timestamp;
         }

         try
         {
            this.sleep(555);
         }
         catch(InterruptedException exc)
         {
            keep_running = false;
         }
      }
   }