Please Check the following css and scripts are there in the header section of the page
<script type="text/javascript" src="Scripts/jquery-1.9.0.min.js"></script> <link href="bootstrap/css/bootstrap.css" rel="Stylesheet" /> <link href="bootstrap/css/bootstrap-theme.css" rel="Stylesheet" /> <script type="text/javascript" src="bootstrap/js/bootstrap.js"></script>
Use the following code:
</pre> <div class="btn-group"><button class="btn btn-default dropdown-toggle" type="button" data-toggle="dropdown"> Dropdown </button> <ul class="dropdown-menu"> <li><a href="#">Dropdown link</a></li> <li><a href="#">Dropdown link</a></li> </ul> </div> <pre>
Reference taken from the following site.
http://getbootstrap.com/components/#dropdowns