working bootply link : http://www.bootply.com/105915#
you have to use button class for button
toggle-collapse for toggling the nav menu on click of button
and media query to only display the button for small screen
<nav class="navbar navbar-inverse navbar-fixed-top">
<div class="navbar-header">
<a class="navbar-brand" href="#">Brand</a>
<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>
</div>
<div class="navbar-collapse collapse">
<ul class="nav navbar-nav">
<li class="active"><a href="#">Home</a></li>
<li><a href="#about">About</a></li>
<li><a href="#contact">Contact</a></li>
</ul>
<div class="navbar-header navbar-right">
<p class="navbar-text">
<a href="#" class="navbar-link">Username</a>
</p>
</div>
</div>
</nav>
//css
body {
padding-top:70px;
}
@media (max-width: 990px) {
.navbar-header {
float: none;
}
.navbar-toggle {
display: block;
}
.navbar-collapse {
border-top: 1px solid transparent;
box-shadow: inset 0 1px 0 rgba(255,255,255,0.1);
}
.navbar-collapse.collapse {
display: none!important;
}
.navbar-nav {
float: none!important;
margin: 7.5px -15px;
}
.navbar-nav>li {
float: none;
}
.navbar-nav>li>a {
padding-top: 10px;
padding-bottom: 10px;
}
}