Javascript Rails 3.2.1

I'm looking to set this up:
http://robertnyman.com/2010/12/16/utilizing-the-html5-file-api-to-choose-upload-preview-and-see-progress-for-multiple-files/

So I created a file called upload.js in my assets/javascript directory
with the applicable js code (on the above site). I added in the
new.html.erb the html code.

The view populates but the Javascript is not working properly. I have
upload.js included in my application.html.erb file. Why might this be?