I have little PHP experience and need a bit of help.

I found a nice little PHP test application, but it doesn't do everything I need. It is a simple little multiple-choice exam, which scores the test when completed. I would like for the application to add the following function:

- if the score is less than a 70% (7 out of 10), the application needs to tell the tester to retake the exam and redirect them back to the test.
- if the score is 70% or greater, the application needs to congratulate the tester and send them back to the home page.

What would I to add to the code? Would I place the code in the function.inc file?