I upload file = Plupload . I checked varibles $_FILES, $_POST, $this->data , all is empty and !isset please help me

  function mod_uploadImg($id = null){
        if (!$id){
              return false;
        }
        if (!empty($_POST)){
              CakeLog::write('activity', 'file exist');
        }
        if (isset($_FILES['file']['tmp_name']) && is_uploaded_file($_FILES['file']['tmp_name'])){
              CakeLog::write('activity', 'file exist');
        }
        if (!empty($this->data)){
              CakeLog::write('activity', '$this->data');
        }

        if (!empty($_FILES)){
        CakeLog::write('activity', '$_FILES');
        }
  }

(Script Dont koymak gerekir gibi görünüyor olsa da) ben formda multipart / form-data koyduk