<! DOCTYPE html>
<meta charset= "Utf-8" >
<meta http-equiv= "x-ua-compatible" content= "Ie=edge" >
<meta name= "viewport" content= "Width=device-width, initial-scale=1" >
<title>hello world</title>
<link rel= ' stylesheet ' href= "Http://netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css" >
<body>
<nav class= "NavBar navbar-default" role= "Navigation" >
<div class= "Container-fluid" >
<!--Brand and toggle get grouped for better mobile display--
<div class= "Navbar-header" >
<button type= "button" class= "Navbar-toggle collapsed" data-toggle= "collapse" data-target= "# Bs-example-navbar-collapse-1 ">
<span class= "Sr-only" >toggle navigation</span>
<span class= "Icon-bar" ></span>
<span class= "Icon-bar" ></span>
<span class= "Icon-bar" ></span>
</button>
<a class= "Navbar-brand" href= "#" > A management System </a>
</div>
<!--Collect the Nav links, forms, and other content for toggling
<div class= "Collapse navbar-collapse" id= "bs-example-navbar-collapse-1" >
<ul class= "Nav navbar-nav" >
<li class= "Active" ><a href= "#" > Home </a></li>
<li class= "Dropdown" >
<a href= "#" class= "Dropdown-toggle" data-toggle= "dropdown" > Function <span class= "caret" ></span></a >
<ul class= "Dropdown-menu" role= "Menu" >
<li class= "Disabled" ><a href= "#" > Business Functions </a></li>
<li><a href= "#" > Information creation </a></li>
<li><a href= "#" > Information Query </a></li>
<li><a href= "#" > Information Management </a></li>
<li class= "Divider" ></li>
<li class= "Disabled" ><a href= "#" > System settings </a></li>
<li><a href= "#" > Settings </a></li>
</ul>
</li>
</ul>
<form class= "Navbar-form navbar-right" role= "Search" >
<div class= "Form-group" >
<input type= "text" class= "Form-control" placeholder= "username" >
<input type= "Password" class= "Form-control" placeholder= "password" >
</div>
<button type= "Submit" class= "btn btn-default" > Login </button>
</form>
</div><!--/.navbar-collapse--
</div><!--/.container-fluid--
</nav>
<script src= ' http://cdn.bootcss.com/jquery/1.11.1/jquery.min.js ' ></script>
<script src= ' http://cdn.bootcss.com/bootstrap/3.2.0/js/bootstrap.min.js ' ></script>
</body>
Bootstrap navigation Menu