Request for help =>

Hey everybody, I've been hacking away on some scripts to do various things (primarily, a job listing and faculty listing database for my work, Oregon State University), and I've got to admit, I'm pretty new to this stuff, and a lot of it I'm just hacking away at. For instance, today, I threw together some session stuff to verify users yadda yadda yadda. I see a lot of code come through the list that looks. well, more defensive than mine. I was wondering if someone (or a few people) might be so kind as to take a look at my code and let me know if there are things that I'm missing, doing wrong, or doing right. Any bit of help would be appreciated. Thanks very much, Ben