ajax文件上载

 <script type="text/javascript" src="fileuploader.js"></script>
   <script type="text/javascript" src="jquery-1.4.2.min.js"></script>

<div id="photo_upload">
      <div id="file-uploader_photo">       
       <noscript>          
       <p>Please enable JavaScript to use file uploader.</p>
       <!-- or put a simple form for upload here -->
       </noscript>         
      </div>
     </div>

<script language='javascript'>
new qq.FileUploader({
   element: $('#file-uploader_photo')[0],
   action: 'upload.php',
   onSubmit: function(id, fileName){
    ContentWindow.params['title'] = fileName;
    CDNAPI.validate(ContentWindow.params);
    ContentWindow.uploader.setParams(ContentWindow.params);
   },
   onComplete: function(id, fileName, content_data){
    // create content object in Gib
    App.addNewContent(content_data);
   },
   template:'<div class="qq-uploader">' + 
    '<div class="qq-upload-drop-area"><span>Drop files here to upload</span></div>' +
    '<div class="qq-upload-button ui-widget-content ui-button ui-corner-all ui-state-default">Upload files</div>' +
    '<ul class="qq-upload-list"></ul>' + 
        '</div>'
  });
</script>

但是这个代码给了我一个错误,这个元素没有定义 [此错误时中断]如果(此_元素.节点类型!= 1){

用这个。。。 http://valums.com/ajax-upload/