[Haskell-beginners] playing around with code from the tutorials for Yesod - and this came up.

This code I am using can be seen from this url. http://docs.yesodweb.com/yesod/tutorial/ajax.html I downloaded it from the site, tried to compile and got this error. ajax.lhs:55:29: Not in scope: `style_css' ajax.lhs:55:29: Not in scope: `script_js' Here is line 55

hamletToContent [$hamlet|

I'm lost when it comes to figuring out why this won't compile? Changes in interface since the tutorial was written maybe? Any help would be greatly appreciated.