有时，选择select某项时，要显示一个文本说明，不同的选项出现不同的文本说明，可用jquery实现。
$(document).ready( function(){selectval();});
function selectval()
{
$( "select").change( function(){
$(".ii").remove();
var t=$( this).children( "[@selected]").html();
var a=['111','222','333'];
var b='';
$.each(a, function(){
if(t!= this){b=b+ this+'<br>'}
});
$( "select").after('<div class="ii">'+b+'</div>');
});
}
< div >
         < select >
         < option value ="aa" >111 </option>
         < option value ="bb" >222 </option>
         < option value ="cc" >333 </option>
         </select>
         </div>
当然还有这种情况~！
< html xmlns ="http://www.w3.org/1999/xhtml" >
< head runat ="server" >
         < title >无标题页 </title>

         < . type ="text/." src ="../JS/jquery.js" > </.>
                 < . language =. >
         $(document).ready(function(){selectval();});
         function selectval(){
         $("#dis").change(function(){
         $('.1').hide();
         $('.2').hide();
         var s=$(this).children("[@selected]").html();
         var c=$(this).children("[@selected]").val();
         var a=['aaaaa','bbbbb','cccc'];
         var b='';
         $.each(a,function(){if(this!=s){
         $('.'+c).show();
         }});
         })
         }
                 </.>
</head>
< body >
         < form id ="form1" runat ="server" >
                 < div id ="content" class ="test" >
                         < h1 >
                                test </h1>
                         < table class ="bd_cmn_style" >
                                 < tbody >
                                         < tr class ="1" style ="display: none" >
                                                 < td >
                                                        aaaaaaa </td>
                                                 < td >
                                                        bbbbbbb </td>
                                         </tr>
                                         < tr class ="2" style ="display: none" >
                                                 < td >
                                                        ccccccc </td>
                                         </tr>
                                         < tr >
                                                 < td >
                                                        显示隐藏
                                                         < select id ="dis" >
                                                                 < option value ="1" >aaaaa </option>
                                                                 < option value ="2" >bbbbb </option>
                                                                 < option value ="3" >cccc </option>
                                                         </select>
                                                 </td>
                                         </tr>
                                 </tbody>
                         </table>
                 </div>
         </form>
</body>
</html>