The following code shows how to create split button dropdowns.
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'
src='http://code.jquery.com/jquery-git2.js'></script>
<link rel="stylesheet" type="text/css"
href="http://getbootstrap.com/assets/css/docs.css">
<link rel="stylesheet" type="text/css"
href="http://netdna.bootstrapcdn.com/bootstrap/3.0.0-rc1/css/bootstrap.min.css">
<script type='text/javascript'
src="http://netdna.bootstrapcdn.com/bootstrap/3.0.0-rc1/js/bootstrap.min.js"></script>
</head><!--from w w w. j ava 2s. c o m-->
<body style='margin:30px'>
<h3 id="btn-groups-justified">Split button dropdowns</h3>
<div class="btn-group">
<button type="button" class="btn btn-default dropdown-toggle"
data-toggle="dropdown">
Action <span class="caret"></span>
</button>
<ul class="dropdown-menu">
<li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li class="divider"></li>
<li><a href="#">Separated link</a></li>
</ul>
</div>
</body>
</html>