Thumbs_up Gem，ajax的一个小问题

前几天我看到了这个链接，我决定通过ajax实现这个投票系统：JQuery+thumbs_up gem render vote count。但问题是，我几乎是一步一步地遵循它，但ajax似乎不起作用。有人能帮忙吗？非常感谢。

Micropost控制器

class MicropostsController < ApplicationController
  def vote_up
    @micropost = Micropost.find(params[:id])
    current_user.vote_exclusively_for(@micropost)
  end
  def vote_down
    @micropost = Micropost.find(params[:id])
    current_user.vote_exclusively_against(@micropost)
  end
end

votecount.html.erb

<div class='Counter'>
<span class='CounterNum'><%= @micropost.votes_for %></span>
<a href="#" class='CounterButton b2' updown="up" theid="123">
<span class='CounterIcon'></span>
</a>
<a href="#" class='CounterButton b2' updown="down" theid="123">
<span class='CounterIcon'></span>
</a>
</div>

votecount.js

$(document).ready(function(){
    $(".CounterButton").click(function() {
        var val = $(this).attr('updown');
        var theid = $(this).attr('theid');
        if (val == "up") {
            console.log('up');
        } else {
            console.log('down');
        }
    });​
});