关于bootstrap的form表单的输入框间距样式

<!-- 模态弹出窗内容 -->
            <div class="modal" tabindex="-1" role="dialog"
                aria-labelledby="myLargeModalLabel" aria-hidden="true"
                id="mymodal-link">
                <div class="modal-dialog">
                    <div class="modal-content">
                        <div class="modal-header">
                            <button type="button" class="close" data-dismiss="modal">
                                <span aria-hidden="true">&times;</span><span class="sr-only">Close</span>
                            </button>
                            <h4 class="modal-title">个人信息</h4>
                        </div>
                        <div class="modal-body">
                        <form action="modifyoneteacher.do" class="form-horizontal" role="form">
                            <div class="form-group">
                                <label for="uname" class="col-sm-2 control-label">用户名</label>
                            <div class="col-sm-9">
                                <input type="text" readonly="readonly"
                                    value="Jhon Deo Alex" class="form-control" id="uname" name="uname">
                            </div>
                            </div>
                            <div class="form-group">
                                <label for="pwd" class="col-sm-2 control-label">密码</label>
                            <div class="col-sm-9">
                                <input type="text" readonly="readonly"
                                    value="111asda55" class="form-control" id="pwd" name="pwd">
                            </div>
                            </div>
                    </form>
                        </div>
                        <div class="modal-footer">
                            <button type="button" class="btn btn-default"
                                data-dismiss="modal">修改</button>
                            <button type="button" class="btn btn-primary">保存</button>
                        </div>
                    </div>
                </div>
            </div>