Replacing $_HTTP_GET_VARS with $_GET-Collection of common programming errors

This is a question about setting up variables in an array for a personal memory aid project analogous to the old paper-based flash cards, which I now want to dust off. A PHP programmer at my old work 5 years ago helped write the page – alas I have long since lost contact, and my PHP skills are rudimentary at best.

Current Code (PHP4)