Aah, sorry I'm taking so long on this. I'm working on a new tutorial that'll help you with your problem though, I promise.
I did find the line of code I used, and I'm refraining from posting it just yet because 1) 2 hours of Calculus on my second day of school burned me out just a little, and 2) it'd confuse you to the point of you probably giving up on it if I didn't explain myself.