JQuery on Rails - get around invalid authenticity token

##put this in your helper

# Passes the authenticity token for use in javascript
def yield_authenticity_token
  if protect_against_forgery?
    <<JAVASCRIPT
<script type='text/javascript'>
//<![CDATA[
window._auth_token_name = "#{request_forgery_protection_token}";
window._auth_token = "#{form_authenticity_token}";
//]]>
</script>
JAVASCRIPT
  end
end 

##put this at the top of your layout file

  <%= yield_authenticity_token %>

##run this JS on page load

   // All non-GET requests will add the authenticity token
   // if not already present in the data packet
   $("body").bind("ajaxSend", function(elm, xhr, s) {
   if (s.type == "GET") return;
   if (s.data && s.data.match(new RegExp("\\b" + window._auth_token_name + "="))) return;
   if (s.data) {
   s.data = s.data + "&";
   } else {
   s.data = "";
   // if there was no data, jQuery didn't set the content-type
   xhr.setRequestHeader("Content-Type", s.contentType);
   }
   s.data = s.data + encodeURIComponent(window._auth_token_name)
   + "=" + encodeURIComponent(window._auth_token);
   });