EasyUI中使用Uploadity问题

<div id="UploadPage" class="easyui-layout" fit="true">
    <div region="west" split="true" title="目录" style="width: 200px;">
        <ul id="UploadTree" class="ztree">
        </ul>
    </div>
    <div region="center">
        <div id="tb2" class="operButton">
            <div style="position: absolute; z-index: 99999; left: 170px; top: 2px;">
                <input id="file_upload" name="file_upload" type="file" multiple="true" />
            </div>
        </div>
        <table id="upload_datagrid" data-options="toolbar:‘tb2‘">
        </table>
    </div>
</div>
</div> 

<div id="UploadPage" class="easyui-layout" fit="true">
    <div region="west" split="true" title="目录" style="width: 200px;">
        <ul id="UploadTree" class="ztree">
        </ul>
    </div>
    <div region="center">
        <div id="subcontainer" class="easyui-layout" fit="true">
            <div data-options="region:‘north‘,border:false" style="height: 28px; overflow: hidden;">
                <div id="tb2" class="operButton">
                    <div style="position: absolute; z-index: 99999; left: 170px; top: 2px;">
                        <input id="file_upload" name="file_upload" type="file" multiple="true" />
                    </div>
                </div>
            </div>
            <div data-options="region:‘center‘,border:false,fit:true">
                <table id="upload_datagrid">
                </table>
            </div>
        </div>
    </div>
</div>