private void SaveButtonClick(object sender)
        {
            if (this.isProperAppointment())
            {
                MyAppointment.Title = NewTitle;
                //MyAppointment.Message = NewMessage;
                MyAppointment.StartTime = new DateTime(MyAppointment.StartTime.Year, MyAppointment.StartTime.Month, MyAppointment.StartTime.Day, NewFromH, NewFromM, 0);
                MyAppointment.EndTime   = new DateTime(MyAppointment.StartTime.Year, MyAppointment.StartTime.Month, MyAppointment.StartTime.Day, NewToH, NewToM, 0);

                try
                {
                    if (!OldEvent)
                    {
                        CalendarModel.AddAppointment(MyAppointment);
                    }
                    else
                    {
                        CalendarModel.UpdateAppointment(MyAppointment);
                    }

                    ((Window)sender).Close();
                }
                catch (Exception e)
                {
                    Error     = true;
                    ErrorText = "Unfortunely appointment did not save becouse of " + e.Message + ". Please refresh";
                }
            }
        }