问twitter bootstrap问题:右对齐下拉标题中的插入符号

EN

                    <div class="btn-group cust-dropdown">
                    <button type="button" class="btn btn-default dropdown-toggle cust-dropdown" data-toggle="dropdown"><span class="caret pull-right"></span><span>test</span>
                    </button>
                    <ul class="dropdown-menu" role="menu">
                        <li><a href="#">test</a></li>
                        <li><a href="#">tes2</a></li>
                        <li><a href="#">test3</a></li>
                    </ul>
                </div>

.cust-dropdown {
width: 200px;}