bootstrap 3.1.1 navbar wont collapse on phone - css

Question

I have the following code. on phone, the navbar wont collapse after expanding, I have to click the button for it to toggle the style. any Idea?
<div class="navbar navbar-inverse navbar-fixed-top">
<div class="container">
<div class="navbar-header">
<a ui-sref="default" class="navbar-brand"></a>
<button class="navbar-toggle" type="button" data-toggle="collapse" data-target="#navbar-main">
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
</div>
<div class="collapse navbar-collapse" id="navbar-main">
<ul class="nav navbar-nav">
<li ng-repeat="top in topnav" ng-class="{active: isActive(top.view), dropdown:top.subnav.length>=0}">
<a ui-sref="{{top.state}}" ng-show="top.subnav.length==0">{{top.name}}</a>
{{top.name}} <b class="caret"></b>
<ul class="dropdown-menu" ng-show="top.subnav.length > 0">
<li ng-repeat="sub in top.subnav">
<a ui-sref="{{sub.state}}">{{sub.name}}</a>
</li>
</ul>
</li>
</ul>
</div>
</div>

Answer 1

Working Fiddle
Just use this;
<div class="navbar navbar-inverse">
<div class="container">
<div class="navbar-header">
<button data-target=".navbar-collapse" data-toggle="collapse" class="navbar-toggle" type="button">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
Project name
</div>
<div class="navbar-collapse collapse">
<ul class="nav navbar-nav">
<li class="active">Home</li>
<li>About</li>
<li>Contact</li>
<li class="dropdown">
<a data-toggle="dropdown" class="dropdown-toggle" href="#">Dropdown <b class="caret"></b></a>
<ul class="dropdown-menu">
<li>Action</li>
<li>Another action</li>
<li>Something else here</li>
<li class="divider"></li>
<li class="dropdown-header">Nav header</li>
<li>Separated link</li>
<li>One more separated link</li>
</ul>
</li>
</ul>
</div><!--/.nav-collapse -->
</div>
</div>

Answer 2

did u include bootstrap.min.js?
Its required for drop down and collapse menu.
<script src="//netdna.bootstrapcdn.com/bootstrap/3.1.1/js/bootstrap.min.js"></script>