/// <summary>
        /// Validate values of person data
        /// </summary>
        /// <param name="values">List of strings to validate</param>
        /// <returns>True if values are valid, in other case false</returns>
        public bool validateValues(ParamsForRegister values)
        {
            bool res = true;

            new List <String> {
                values.name, values.surname, values.username, values.password, values.group, values.zal, values.ticket
            }.ForEach(value =>
            {
                if (String.IsNullOrWhiteSpace(value))
                {
                    res = false;
                }
            });
            if (values.password != values.passwordRepeat)
            {
                res = false;
            }
            long temp;

            if (!long.TryParse(values.ticket, out temp))
            {
                res = false;
            }
            if (!long.TryParse(values.zal, out temp))
            {
                res = false;
            }
            return(res);
        }
 /// <summary>
 /// Register user with adding one to database
 /// </summary>
 /// <param name="name">Name of new user</param>
 /// <param name="surname">Surname of new user</param>
 /// <param name="zal">Student ticket number of new user</param>
 /// <param name="username">Username of new user</param>
 /// <param name="password">Password of new user</param>
 /// <returns></returns>
 public bool registerUser(ParamsForRegister values)
 {
     Model.Person person = new Model.Person {
         Name = values.name, Surname = values.surname, Password = values.password, Photo = userPhoto, Username = values.username
     };
     Model.Student student = new Model.Student {
         TicketNumber = long.Parse(values.ticket), ReportCard = long.Parse(values.zal), PersonID = values.username, GroupID = values.group
     };
     if (service.LoadLogInPersonAsync(values.username) == null)
     {
         service.CreatePersonAsync(person).Wait();
         service.CreateStudentAsync(student).Wait();
         return(true);
     }
     else
     {
         return(false);
     }
 }