The following code creates a basic drop down as shown below
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
<div class="dropdown">
<button class="btn btn-primary dropdown-toggle" type="button" data-toggle="dropdown">Dropdown Menu
<span class="caret"></span></button>
<ul class="dropdown-menu">
<li><a href="#">Menu item 1</a></li>
<li><a href="#">Menu item 2</a></li>
<li><a href="#">Menu item 3</a></li>
</ul>
</div>
</div>
</body>
</html>
