<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="http://www.mamicode.com/#" 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>

 1 <style type="text/css">
 2         .isbnt
 3         {
 4             float: left;
 5             margin-left: 10px;
 6         }
 7         .bnt
 8         {
 9             margin: 0 auto;
10             width: 500px;
11             height: 20px;
12         }
13     </style>