bootstrap 2.x dropdown在外面点击时隐藏

Question

bootstrap 2.x下拉隐藏当点击外面时想要保持打开下拉列表。以下是示例html。

<ul class="pull-left">
    <li class="dropdown open" id="stayOpen"><a href="javascript:;" class="btn btn-inverse dropdown-toggle" data-toggle="dropdown" title="Notes"><i class="icon-list icon-white" role="button"></i></a>
     <ul class="dropdown-menu" role="menu">
       <li><h5>Dropdown options</h5></li>
      </ul>
   </li>    
</ul>