protected async Task NavigateToEmail(Meeting meeting, string action, string comment = null)
        {
            using (new Loading(this))
            {
                var response = await OfficeService.CreateInvitationResponse(meeting, action);

                if (response != null)
                {
                    var parameter = Tuple.Create(response, action, comment);
                    await NavigateTo("Email", parameter);
                }
                else
                {
                    await MessageDialog(GetString("CantReply"));
                }
            }
        }