no, you do not need to edit the helper _PHP file.
The if statement should be added to the profile page.
Looking at the login page you have sent, you have not edited the Authenticate user behavior to store the user level in a session, you need to complete that step.
In my last reply, i suggested going back a step and instead of editing the user registration files to use basic security assist pages and implement the user level tutorial on those to get familiar with what the tutorial is trying to teach.
I really do think you will get more out of this method, once you understand how user level authentication works, it will be easier to edit the user registration solution pack.