undefined != null

www/js/autodoc.js

@@ -253,7 +253,7 @@ function upload_read_event(e) {
 function upload_status() {
 
   $.each(temp.upload, function (id, file) {
-    if (!$('.autodoc_upload_status_' + id)) {
+    if ($('.autodoc_upload_status_' + id) === 'undefined') {
       var obj = $(".autodoc_template_progress").children().clone();
       $('.autodoc_upload_status').append(obj);
     }