背景图片显示问题

为什么运行的时候显示不了背景图片?
<table>
           <tr>
           <td style="width:574px; height:246px; background-attachment: fixed; background-image: url(images/Login.jpg); background-repeat: no-repeat;">
                 中间是控件的布局                              
                </td>
                </tr>            
                </table>