I have a bunch of errors in my Processing2+ program

I have a bunch of errors in my Processing2+ program

Are you the founder of the website called: http://processing.org/? if so
then I need help with The Mario Game Tutorial found on this website.
I can't find any information about the author who wrote the mario game
tutorial using a programming language called Processing 2+.
How do I find information about the author who wrote this Mario Game
Tutorial for Processing 2+, so I can have him or her help me finish this
tutorial?
when I run the mario game tutorial program, I get a fuction call error,
stating that The function clearScreen() does not exist, so I rem out The
function clearScreen() and a bunch of new errors came up stating:
The function addScreen(String, Mario.MainLevel) does not exist
cannot find a class or type named "Level"
unexpected token:(
cannot find a class or type named "LevelLayer"
how do I fix the errors listed above?