在uncollapsed（javascript或JQuery）时添加必需的属性

Question

我们得到了下面的代码，我们希望在折叠属性= false时需要输入。

                                                                                                                                                    

                    <div id="memberThree" class="panel-collapse collapse" aria-labelledby="headingThree">
                        <div class="panel-body">
                            <div class="input-group col-xs-2">
                                <label>Voornaam:</label>
                                <input type="text" class="form-control" placeholder="Voornaam" id="teamlid3Voornaam">
                            </div>