bootstrap布局两列或者多列表单

                        <div class="form-group">
                            <label for="starttime" class="col-sm-2 control-label">实际开始时间</label>
                            <div class="col-md-4">
                                <input class="form-control" type="text" id="starttime" readonly="readonly" onchange="checkNull(this,‘submitButton‘)" />
                            </div>
                            <label for="endtime" class="col-sm-2 control-label">实际结束时间</label>
                            <div class="col-md-4">
                                <input class="form-control" type="text" id="endtime" readonly="readonly" onchange="checkNull(this,‘submitButton‘)" />
                            </div>
                        </div>