title: How can I add the custom button in the select box?
body: <p>How can I add the custom button in the select box? Just like the clear button?</p>
  
  <p>Because I'm using ajax, and want to save cache in the browser.
  <a href="http://i.stack.imgur.com/8BBgk.png" rel="nofollow">enter image description here</a></p>