[StructLayout(LayoutKind.Sequential, Pack = 1, Size = 116, CharSet = CharSet.Ansi)]
    public struct RequestLogin
    {
        private PacketHeader header;

        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 16)]
        private string userName;

        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 12)]
        private string userPassword;

        #region Proprierties
        public PacketHeader Header
        {
            get { return header; }
            set { header = value; }
        }

        public string UserName
        {
            get { return this.userName; }
            set { this.userName = value; }
        }

        public string UserPassword
        {
            get { return this.userPassword; }
            set { this.userPassword = value; }
        }
        #endregion
    }