Code review for first script

Hi all. I am relatively new to SE, and just getting started with the PG and C#, but not new to programming at all. I spent a bit of time this evening reading the docs and some of the posts in this forum (I will certainly read more of them, as there is a lot of good info here) and I worked out my first sort of test script. I value peer review and am mostly just interested in whether I have the basics down correctly or not. Can folks take a look at my script and point out any bad patterns...

Code review for first script