<link href="//netdna.bootstrapcdn.com/bootstrap/3.0.3/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//netdna.bootstrapcdn.com/bootstrap/3.0.3/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<!------ Include the above in your HEAD tag ---------->
<a href="#" class="btn btn-block btn-warning">Click Here if video doesn't exist</a>