I can’t see anything wrong with your code, you should be able to do this. As SCape_games said, make sure you have them checked in your Build Settings so they are in fact included. But I don’t think that would account for that particular error message.
One note though: It’s common to Capitalize the First letter of a Function , and have small case for the first letter of a variableName to keep them cognitively different. Just a convention most of us follow.