/**
  * clears multiple tasks for a given done_date
  * *
  */
 public function clearTasksAction()
 {
     $this->_helper->layout->disableLayout();
     $this->_helper->viewRenderer->setNoRender();
     if (!$this->getRequest()->isPost()) {
         return false;
     }
     $post_data = $this->getRequest()->getPost();
     $task_ids = $post_data['task_ids'];
     $done_date = $post_data['done_date'];
     $matterModel = new Application_Model_Matter();
     $result = $matterModel->clearTasks($task_ids, $done_date);
     echo $result;
 }