根据单击的按钮获取表单内的输入值

I've got the following form:

我有以下表格:

<div>
  <form name="ajaxformname" id="ajaxform" action="/request" method="POST">
    AJAX:
    <input id="btn1" name="feeling" type="submit" value="Fine">
    <input id="btn2" name="feeling" type="submit" value="Neutral">
    <input id="btn3" name="feeling" type="submit" value="Bad">
  </form>
</div>
<div>