private void ChallengesDataGridView_CellDoubleClick(object sender, DataGridViewCellEventArgs e)
        {
            if (e.RowIndex > -1 && e.ColumnIndex > -1)
            {
                int    minimumAge = Int32.Parse(ChallengesDataGridView.Rows[e.RowIndex].Cells[0].Value.ToString());
                int    maximumAge = Int32.Parse(ChallengesDataGridView.Rows[e.RowIndex].Cells[1].Value.ToString());
                string name       = ChallengesDataGridView.Rows[e.RowIndex].Cells[2].Value.ToString();

                Challenge             challenge    = ctrl.GetChallengeByProperties(minimumAge, maximumAge, name);
                ChallengeChildrenData childrenData = new ChallengeChildrenData(ctrl.GetChildrenById(challenge.Id));
                childrenData.Show();
            }
        }