Hi Nicholas!
It sounds as if there is just a minor typo in the code that you’ve typed. You might try comparing what you’ve typed with the code in the back of the book. It might be something as simple as a misspelling or maybe some letters aren’t capitalized as they need to be.
If you’d like me to look it over, I’d be happy to. You can use the share link feature in 3DE to paste a link to your code here. You can also read through some more suggestions here.
Not to worry – we can definitely get it working 
-Chris