Dropdown

<!-- Single button -->
<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" role="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>

<!-- Split button -->
<div class="btn-group">
            <button type="button" class="btn btn-danger">Action</button>
            <button type="button" class="btn btn-danger dropdown-toggle" data-toggle="dropdown">
            <span class="caret"></span>
            <span class="sr-only">Toggle Dropdown</span>
            </button>
            <ul class="dropdown-menu" role="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>

$('.dropdown-toggle').dropdown()