ASP.NET

[Serializable]
public class ResponseCode
{
	public string ErrorCode
	{
		return _errorCode;
	}
	public string ErrorDescription
	{
		get { return _errDescription; }
	}
}

[Serializable]
public class BaseResponse
{
	public ResponseCode Result
	{
		get { return _respCode; }
		set { _respCode = value; }
	}
	
}

public class AuthenticationResponse : BaseResponse
{
	public int Credit
	{
		get { return _credit; }
		set { _credit = value; }
	}
	public int UserID
	{
		get { return _userID; }
		set { _userID = value; }
	}

}

<AuthenticationResponse>
  <Result>
	<ErrorCode>1020300</ErrorCode>
	<ErrorDescription>Invalid username or password</ErrorDescription>
  </Result
  <Credit>0</Credit>
  <UserID>0</UserID>
</AuthenticationResponse>

<AuthenticationResponse>
  <Result />
  <Credit>0</Credit>
  <UserID>0</UserID>
</AuthenticationResponse>