jquery 添加html标签

<script type="text/javascript">
        var sss = 1;
        function addFile() {
            if (sss < 20) {
                var str = ' <span id = row' + sss + '><br/><INPUT type="file" style="WIDTH: 222px; HEIGHT: 20px" size="50" NAME="File">&nbsp;<span style="line-height:25px;">文件说明：<input type="text" id="pic' + sss + '" name="pic' + sss + '" value="" style="WIDTH: 322px; HEIGHT: 20px" size="50"   /><a href="#" onclick=deleteRow(row' + sss + ')>删除<a/></span>';
                document.getElementById('P1').insertAdjacentHTML("beforeEnd", str);
            }
            else {
                alert("您一次最多只能上传20个文件！");
            }
            sss++;
        }

        function deleteRow(e) {
            //alert("成功删除第" + e + "行");
            var obj = document.getElementById(e.id);
            //    obj.removeNode(e);
            obj.remove(e);
            sss--;
        }

    </script>

<style type="text/css">
        .isbnt
        {
            float: left;
            margin-left: 10px;
        }
        .bnt
        {
            margin: 0 auto;
             500px;
            height: 20px;
        }
    </style>

   　　　　<tr>
                    <th>
                        文 件：
                    </th>
                    <td colspan="5">
                        <p id="P1">
                            <input id="file" style=" 222px;" type="file" size="42" name="File1" runat="server" />
                            <span>文件说明：
                                <input type="text" id="pic0" name="pic0" value="" style=" 322px;" size="50" /></span>
                        </p>
                        <input type="button" value="继续上传" onclick="addFile()" style=" 69px; height: 20px" />
                    </td>
                </tr>