如何显示警报并防止显示警报

Question

当表单中的选择选项通过（W3）时，如果未选择单选按钮（请选择单选），如何弹出警报消息。 另外，当选择选项被拒绝（W5）时，如何防止显示警报并显示文本区域

var Privileges = jQuery('#one');
var select = this.value;
Privileges.change(function() {
  if ($(this).val() == 'W5') {
    $('.resources').show();
  } else
    $('.resources').hide();
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="row">
  <div class="col-md-6"></div>
  <div class="col-md-6">
    <div class="form-group ">
      <h5><b>Remark :</b></h5>
      {{Form::select('remark', ['W3' => 'Pass', 'W5' => 'Reject'], 'W3', ['class' => 'form-control', 'id' => 'one'])}}
    </div>
  </div>

  <div class="col-md-6"></div>
  <div class="col-md-6">
    <div class="form-line resources" style="display: none; margin-top: 20px !important" id="two">
      <h5><b>Note :</b></h5>
      <textarea id="txtArea" name="notep6" class="form-control" rows="5" cols="3"></textarea>
    </div>
  </div>
</div>

<div class="row">
  <div class="col-md-10"></div>
  <div class="col-md-2">
    <input type="submit" value="Save" class="btn btn-lg btn-success btn-block" id="submit_tenure" style="cursor:pointer;"> {{ csrf_field() }}
  </div>
</div>