jsp中實現帶滾動條的table表格

<!--div比table的width要小滾動條才會顯示-->
            <div class="box-vertical" style="width: 400px; max-height: 240px; overflow:auto;">
            <table id="tab_1" style="width: 400px;" cellpadding="0"
            cellspacing="1" class="formtable">
            <tr>
                <th align="center">序號</th>
                <th align="center">記賬日期</th>
                <th align="center">記賬匯率</th>
            </tr>
             <tbody id="tbd">
            </tbody> 
            </table>
            </div>