/// <summary>
        /// AddNewPerson функція, що вносить дані про користувача який забронював авіаквиток.
        /// </summary>
        public void AddNewPerson()
        {
            var sum = Int32.Parse(new String(string.Join(" ", Seating.Split(' ').ToList()[2]).Where(Char.IsDigit).ToArray()));
            PersonalInformation personalInformation = new PersonalInformation();

            personalInformation.FirstName  = FirstName;
            personalInformation.SecondName = SecondName;
            personalInformation.Document   = Document;
            personalInformation.Gender     = Gender.ToString();
            personalInformation.FlightId   = FlightId;
            personalInformation.BirthDate  = BirthDate;
            personalInformation.Seating    = string.Join(" ", Seating.Split(' ').ToList().GetRange(0, 2)).ToString();
            personalInformation.Login      = Login;
            CountTickets -= 1;

            Clients.Add(personalInformation, sum);

            if (CountTickets == 0)
            {
                Views.Payment menu = new Views.Payment(Login);
                menu.Show();
                CloseWindow();
            }
            else
            {
                Views.Personal_Information personal_Information = new Views.Personal_Information(Login, FlightId, CountTickets);
                personal_Information.Show();
                CloseWindow();
            }
        }