code: function(_url,_mode,_cookie){
              _j0._$request(_url,{
                  type:'json',
                  method:'POST',
                  cookie:_cookie,
                  mode:parseInt(_mode)||0,
                  onload:function(_data){
                      if (!this.__timer) return;
                      this._$dispatchEvent('onuploading',_data);
                      this.__timer = window.setTimeout(
                          _doProgress._$bind(
                              this,_url,_mode,_cookie
                          ),1000
                      );
                  }._$bind(this),
                  onerror:function(_error){
                      if (!this.__timer) return;
                      this.__timer = window.setTimeout(
                          _doProgress._$bind(
                              this,_url,_mode,_cookie
                          ),1000
                      );
                  }._$bind(this)
              });
          }
docs: check upload progress