title: Rails post can't verify CSRF token authenticity
body: <p>I've check this <a href="https://stackoverflow.com/questions/7203304/warning-cant-verify-csrf-token-authenticity-rails">WARNING: Can't verify CSRF token authenticity rails</a>
  but I still can't figure it out why it cause this error.</p>
  
  <p>Here is my <code>ajax</code></p>
  
  <pre><code> $.post(
        "&lt;%= ajax_chats_path %&gt;",
        {timestamp :(new Date()).getTime(),msg: $('#msg').val()},
        function (json) {
        console.log(json);
      });
  </code></pre>
  
  <p>If I add this </p>
  
  <pre><code>skip_before_action :verify_authenticity_token
  </code></pre>
  
  <p>in controller, it can solve this problem.</p>
  
  <p>I am not sure it's the right way to do, because it looks like it may encounter some security attack.  </p>