bootstrap搜索框

<div class="row head">
                <div class="col-lg-12">
                    <div class="input-group">
                        <input type="text" class="form-control" placeholder="搜你想要的">
                        <span class="input-group-btn">
                            <button class="btn btn-info" type="button"><span class="glyphicon glyphicon-search"></span></button>
                        </span>
                    </div>
                </div>
            </div>