怎么用layui实现图片上传

<div>            <button>上传图片</button>            　<input>             <div>                   @@##@@                   <p></p>             </div></div><script>    layui.use([&#39;laypage&#39;, &#39;layer&#39;, &#39;upload&#39;], function () {        var laypage = layui.laypage  //设置配置环境            , layer = layui.layer            , upload = layui.upload             //上传图片        var uploadInst = upload.render({            elem: &#39;#upload&#39;            , url: &#39;/upload/&#39; //改成您自己的上传接口            , before: function (obj) {                //预读本地文件示例，不支持ie8                obj.preview(function (index, file, result) {                    $(&#39;#demo1&#39;).attr(&#39;src&#39;, result); //图片链接（base64）                });            }            , done: function (res) {                //如果上传失败                if (res.code > 0) {                    return layer.msg(&#39;上传失败&#39;);                }                //上传成功            }            , error: function () {                //演示失败状态，并实现重传                var demoText = $(&#39;#demoText&#39;);                demoText.html(&#39;<span style="color: #FF5722;">上传失败                 <a class="layui-btn layui-btn-xs demo-reload">重试&#39;);                demoText.find(&#39;.demo-reload&#39;).on(&#39;click&#39;, function () {                    uploadInst.upload();                });            }        }); }); </script>