private int arrayFind(byte[] arrayin, byte[] arrayref)
    {
      int i = Array.IndexOf(arrayin, arrayref[0]);
      while (i > -1)
      {
        for (int j = 0; j < arrayref.Length && (j + i) < arrayin.Length; j++)
        {
          if (arrayref[j] != arrayin[i + j]) break;
          if (j == arrayref.Length - 1) return i;
        }
        i = Array.IndexOf(arrayin, arrayref[0], i + 1);
      }
      return -1;
    }