The following code shows how to create Expander Menu.
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'
src='http://code.jquery.com/jquery-2.0.2.js'></script>
<link rel="stylesheet" type="text/css"
href="http://getbootstrap.com/dist/css/bootstrap.css">
<script type='text/javascript'
src="http://getbootstrap.com/dist/js/bootstrap.js"></script>
<link rel="stylesheet" type="text/css"
href="http://maxcdn.bootstrapcdn.com/font-awesome/4.1.0/css/font-awesome.min.css">
</head><!--from ww w.j a va 2s.c o m-->
<body>
<div class="navbar navbar-inverse">
<div class="container">
<!-- Header -->
<div class="navbar-header">
<button type="button" class="navbar-toggle" data-toggle="collapse"
data-target=".navbar-collapse">
<span class="icon-bar"></span> <span class="icon-bar"></span> <span
class="icon-bar"></span>
</button>
<a class="navbar-brand" href="#">Bootstrap 3.0 Skeleton</a>
</div>
<!-- Navbar Links -->
<div class="collapse navbar-collapse">
<ul class="nav navbar-nav">
<li><a href="#" data-toggle="collapse" data-target="#demo">
Directory <span class="caret"></span>
</a></li>
<li><a href="#about">About</a></li>
<li><a href="#contact">Contact</a></li>
</ul>
</div>
</div>
</div>
<div id="demo" class="collapse">
<div class="row">
<div class="col-xs-3">
<a href="">Link 1</a>
</div>
<div class="col-xs-3">
<a href="">Link 2</a>
</div>
<div class="col-xs-3">
<a href="">Link 3</a>
</div>
<div class="col-xs-3">
<a href="">Link 1</a>
</div>
<div class="col-xs-3">
<a href="">Link 2</a>
</div>
<div class="col-xs-3">
<a href="">Link 3</a>
</div>
<div class="col-xs-3">
<a href="">Link 1</a>
</div>
<div class="col-xs-3">
<a href="">Link 2</a>
</div>
<div class="col-xs-3">
<a href="">Link 3</a>
</div>
</div>
</div>
<h2>Page Content</h2>
<!-- Post Info -->
<div
style='position: fixed; bottom: 0; left: 0; background: lightgray; width: 100%;'>
About This SO Question: <a
href='http://stackoverflow.com/q/24640251/1366033'>Bootstrap and
expanding menu</a><br /> Fork This Skeleton Here: <a
href='http://jsfiddle.net/KyleMit/kcpma/'>Bootstrap 3.0 Skeleton</a><br />
<div>
</body>
</html>