如何实现动态下拉列表

Question

<select name="LineName" onchange="javascript:main.submit();">
       <%
       _sqlStr="select LINE_NAME from SFIS1.C_LINE_DESC_T";
       _tmpSmt=_con.createStatement();
       _tmpRs=_tmpSmt.executeQuery(_sqlStr);
       while(_tmpRs.next())
       {
       String _tmpLineName=_tmpRs.getString(1);
       out.println("<option value=\""+_tmpLineName+"\"");
       if(_tmpLineName.equals(_lineName))
       out.println("selected");
       out.println(">"+_tmpLineName+"</option>");
       }
       if(_tmpRs!=null)_tmpRs.close();
       if(_tmpSmt!=null)_tmpSmt.close();
       %>
      </select>