static public string ForceJson(object res)
    {
        JavaScriptSerializer js = new JavaScriptSerializer();
        return ( js.Serialize(res) );
    }

    static public byte[] Hash(string plainString, Encoding encoding)
    {
      if (plainString == null)
        throw new ArgumentNullException("plainString");

      if (encoding == null)
        encoding = Encoding.UTF8;

      return Hash(encoding.GetBytes(plainString));
    }

    static public byte[] Hash(byte[] bytes)
    {
      if (bytes == null)
        throw new ArgumentNullException("bytes");
      using (SHA256 algorithm = new SHA256Managed())
      {
        byte[] hashBytes = algorithm.ComputeHash(bytes);
        return hashBytes;
      }
    }

    public string HashToBase64(string plainString, Encoding encoding)
    {
      if (plainString == null) throw new ArgumentNullException("plainString");
      return Convert.ToBase64String(Hash(plainString, encoding));
    }