private void buttonSearch_Click(object sender, EventArgs e) { string SubName; SubName = Convert.ToString(textBoxSubName.Text); if (SubName == "") { MessageBox.Show("Please input name:)"); } else { int k = StudentList.Search(SubName); if (k == -1) { MessageBox.Show("Not Found!"); } else { ShowStudnet ShowStudnetDlg = new ShowStudnet(k); ShowStudnetDlg.Show(); } } }