如何使用jquery将值从drawyer步骤值插入到文本框中

Question

我有一个输入框，我想从下拉列表中的步骤框中插入更新的值。我可以在下拉列表中创建步骤，但不知道如何将这些值插入到框中。

HTML

<input type="text" class="form-control" name="pax" id="pax" placeholder="Adult / Child"/>

<div class="content" style="display:none;">
  <div id="" class="row">
    <div id="" class="col-sm-8">
      <i class="fa fa-user"></i> Adult
    </div>
    <div id="" class="col-sm-4">
      <div class="input-group">
        <span class="input-group-btn">
        <button type="button"  id="WS1dec" class="but btn btn-primary"> - </button></span>
        <input type="number" id="WS1" value="1" class="form-control">
        <span class="input-group-btn">
<button type="button"  id="WS1inc" class="but btn btn-primary"> + </button> 
</span>
      </div>
    </div>
  </div>
  <div id="" class="row">
    <div id="" class="col-sm-8">
      <i class="fa fa-child"></i> Child
    </div>
    <div id="" class="col-sm-4">
      <div class="input-group">
        <span class="input-group-btn">
        <button type="button"  id="WS2dec" class="but btn btn-primary"> - </button></span>
        <input type="number" id="WS2" value="1" class="form-control">
        <span class="input-group-btn">
<button type="button"  id="WS2inc" class="but btn btn-primary"> + </button> 
</span>
      </div>
    </div>
  </div>

</div>

的Javascript

$(document).ready(function() {
  $("#pax").click(function() {
    $(".content").animate({
      height: 'toggle'
    });
  });
});

$(function() {
  $(".but").on("click", function() {
    var id = this.id;
    var fldId = id.substring(0, id.length - 3);
    var inc = id.substring(id.length - 3) == "inc";
    var fld = $("#" + fldId);
    var val = +fld.val();
    if (inc) val++;
    else val--;
    fld.val(val);
  });
  //update textbox
  $('#done').click(function(){
    var adult_pax=$('#WS1').val();
    var child_pax=$('#WS2').val();
    $('#pax').attr('value','Adult:'+adult_pax+" / "+"Child: "+child_pax);
  })
});

这是代码：http://fiddle.jshell.net/3nakeybq/2/