// 검색 버튼이 눌렀을 때 수행되는 함수
    protected void search(object sender, EventArgs e)
    {
        String searchoption   = ddlSearchOption.SelectedValue;
        String search_keyword = txtSearchOptionDetail.Text;

        BoardDAO boarddao = new BoardDAO();


        switch (searchoption)
        {
        // 제목
        case "0":
        {
            reader = boarddao.SelectTitle(search_keyword);
            ViewState["boards"] = reader;
            setBoardList();
            break;
        }

        // 작성자명
        case "1":
        {
            reader = boarddao.SelectWriter(search_keyword);
            ViewState["boards"] = reader;
            setBoardList();
            break;
        }

        // 내용
        case "2":
        {
            reader = boarddao.SelectContent(search_keyword);
            ViewState["boards"] = reader;
            setBoardList();

            break;
        }

        // 전체
        case "3":
        {
            reader = boarddao.SelectSum(search_keyword);
            ViewState["boards"] = reader;
            setBoardList();
            break;
        }

        default:
        {
            ErrorGo("다시 한 번 확인해주세요", "Board_Main.aspx");
            break;
        }
        }
    }