private void btnStart_Click(object sender, EventArgs e) { int maxValue, maxDraw; if (int.TryParse(this.tbMaxValue.Text, out maxValue) && int.TryParse(this.tbMaxDrawn.Text, out maxDraw)) { game = new Lottery(maxValue, maxDraw); this.btnNext.Enabled = true; this.btnAll.Enabled = true; } else { MessageBox.Show("Enter integers"); } }