<title>W3xue教程(w3xue.com)</title>
<link rel="stylesheet" href="/css/bootstrap/bootstrap3.3.7.min.css">
<script src="/js/bootstrap/jquery.min.js"></script>
<script src="/js/bootstrap/bootstrap3.3.7.min.js"></script>
<p> .close 类可以显示一个关闭按钮。</p>
<button type="button" class="close"><span aria-hidden="true">x</span><span class="sr-only">关闭</span></button>