private void RegisterButton_Click(object sender, EventArgs e)
        {
            string name       = NameTextBox.Text;
            string ageText    = AgeTextBox.Text;
            int    age        = Int32.Parse(ageText);
            string challenge1 = "";
            string challenge2 = "";

            if (FirstChallengeComboBox.SelectedItem != null && FirstChallengeComboBox.SelectedIndex != -1)
            {
                challenge1 = FirstChallengeComboBox.SelectedItem.ToString();
            }
            if (SecondChallengeComboBox.SelectedItem != null && SecondChallengeComboBox.SelectedIndex != -1)
            {
                challenge2 = SecondChallengeComboBox.SelectedItem.ToString();
            }
            try
            {
                Child child = ctrl.RegisterChild(name, age, challenge1, challenge2);
                if (child != null)
                {
                    ErrorLabel.Text = "A aparut o eroare ! ";
                }
                else
                {
                    ErrorLabel.Text = "";
                }
            }
            catch (ValidationException exception)
            {
                ErrorLabel.Text = exception.getErrors();
            }
        }