层显示图片问题

<div id="massage_box">
                        <div class="massage" onmousedown="MDown(massage_box)">
                        <div style="width:469px;height:25px;" onmousedown="MDown(massage_box)">
                         <div style="float:left;width:100px;display:inline;padding-top:5px;padding-left:5px;">
                                    相片详细信息</div>
                            <div style="width: 20px; height: 25px; float:right;" >                               
                                <span onclick="massage_box.style.visibility='hidden'; mask.style.visibility='hidden';imgDetail.src='';imgDetail.style.visibility='hidden'"
                                    style="float: right; display: inline; cursor: hand; width: 20px; height: 20px;padding-left:5px;padding-top:5px;">×</span></div>
                         </div>       
                         
                            <div style="margin: 0 auto">
                                <table align="center" >
                                    <tr>
                                        <td colspan="4" align="center" valign="middle" style="height: 286px; width: 447px;">
                                            <img src="" id="imgDetail" style="display:none" />
                                        </td>
                                    </tr>
                                    <tr>
                                        <td align="center" style="height: 28px; color: Black">
                                            上传时间:<span id="spanUpLoadDate" style="color: Black"></span>&nbsp;&nbsp;客户名:<span
                                                id="spanUserName" style="color: Black"></span></td>
                                    </tr>
                                </table>
                            </div>
                        </div>
                    </div>