Navigation tabs

Hi guys. Can anyone tell me what’s wrong with this navigation tabs code. Am I missing part of it? I tried it on a test site and it looks fine but when I click on the different tabs, the contents freeze and do not change. Here is the code.

<!-- Nav tabs -->
<ul class="nav nav-tabs" role="tablist">
<li class="active"><a href="#home" role="tab" data-toggle="tab">Home</a></li>
<li><a href="#profile" role="tab" data-toggle="tab">Profile</a></li>
<li><a href="#messages" role="tab" data-toggle="tab">Messages</a></li>
<li><a href="#settings" role="tab" data-toggle="tab">Settings</a></li>
<div class="tab-content">
<div class="tab-pane fade in active" id="home">...</div>
<div class="tab-pane fade" id="profile">...</div>
<div class="tab-pane fade" id="messages">...</div>
<div class="tab-pane fade" id="settings">...</div>
</div>

Thanks for any help.