private void button1_Click(object sender, EventArgs e) { t.ReadResults(); List <int> nums = new List <int>(); for (int i = 0; i < textBox1.Lines.Length; i++) { int res = 0; if (int.TryParse(textBox1.Lines[i], out res)) { nums.Add(res); } } DisplayHtml(t.PrintListHistories(nums)); textBox1.Clear(); }