internal Account.RegisterData DeserializeRegistrationJsonData(string jsonString)
        {
            var format = "dd/MM/yyyy";
            var dateTimeConverter = new IsoDateTimeConverter { DateTimeFormat = format, Culture = CultureInfo.InvariantCulture };
            var registrationData = JsonConvert.DeserializeObject<Account.RegisterData>(jsonString, dateTimeConverter);

            if (registrationData == null)
                throw new Exception("Can't deserialize json string, which must contain registration data.");

            return registrationData;
        }

        internal KeyValuePair<bool, DataError> CheckRegisterDataFromWeb(Account.RegisterData registerData)
        {
            // login
            if (registerData.Login == null || registerData.Login == String.Empty)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 0, Message = "No login was provided." });

            if (registerData.Login.Length < 4)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 1, Message = "Username must be at least 4 characters length." });

            if (registerData.Login.Length >= 22)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 2, Message = "Username must be not more, than 22 characters length." });

            if (Char.IsNumber(registerData.Login[0]))
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 3, Message = "Username must start with the character, not a number." });

            // email
            if (registerData.Email == null || registerData.Email == String.Empty)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 4, Message = "No email was provided." });

            if (registerData.Email.IndexOf('@') == -1)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 5, Message = "Email must have a `@` character." });

            if (registerData.Email.IndexOf('.') == -1)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 6, Message = "Email must have a `.` character." });

            if (registerData.Email.Length < 6)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 7, Message = "Emailmust be at least 6 characters length." });

            if (registerData.Email.Length >= 50)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 8, Message = "Email must be not more, than 50 characters length." });

            // password
            if (registerData.Password == null || registerData.Password == String.Empty)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 9, Message = "No password was provided." });

            if (registerData.Password.Length < 8)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 10, Message = "Password must be at least 8 characters length." });

            if (registerData.Password.Length >= 30)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 11, Message = "Password must be not more, than 30 characters length." });

            var specialChars = "!@#$%^&*()".ToCharArray();
            if (registerData.Password.IndexOfAny(specialChars) == -1)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 12, Message = "Password must have at least one special character." });

            // personal info
            if (registerData.PersonalInfo == null)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 13, Message = "No personal info was provided." });

            if (registerData.PersonalInfo.BirthDate == null)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 14, Message = "No birthdate was provided." });

            if (registerData.PersonalInfo.Gender == null)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 15, Message = "No gender was provided." });

            if (registerData.PersonalInfo.Name == null || registerData.PersonalInfo.Name == String.Empty)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 16, Message = "No real name was provided." });

            if (registerData.PersonalInfo.Surname == null || registerData.PersonalInfo.Surname == String.Empty)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 17, Message = "No real surname was provided." });

            if (registerData.PersonalInfo.PhoneNumber == null || registerData.PersonalInfo.PhoneNumber == String.Empty)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 18, Message = "No phone number was provided." });

            if (registerData.PersonalInfo.PhoneNumber.Length < 8)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 19, Message = "Phone number must be at least 8 characters length." });

            if (registerData.PersonalInfo.PhoneNumber.Length >= 40)
                return new KeyValuePair<bool, DataError>(false, new DataError { Id = 20, Message = "Phone number must be not more, than 40 characters length." });

            return new KeyValuePair<bool, DataError>(true, null);
        }