private void button_search_Click(object sender, EventArgs e) { listBox_lv4.Items.Clear(); listBox_lv3.Items.Clear(); listBox_lv2.Items.Clear(); listBox_lv1.ClearSelected(); consMgr.setExamLv4BySearch(listBox_lv4, textBox_search_keywords.Text.Trim().Replace(" ", "").Replace(" ", "").Replace(",", ",")); }