Account menu not working in sample_app of rails 3.2 version

I am reading chapter 8 (sign in, sign out) from michael hartl Ruby on
Rails book.

I have deployed my sample_app to heroku. When I check heroku links, In
that account menu not working, drop down list is not coming.

what will be reason for this?Could anyone can help me in this?

Kind regards.

Hassan Schroeder wrote in post #1146084: