This is a script and not a function, therefore you cannot define input arguments. The values are obtained by INPUT, which has a very limited use and usability. There is no comment or help section in the code. It is not working, because the function "shift" is unknown.
@ Sean all constructive feedback helps community members learn how to improve their files. In regards to the quality, we leave it to the community to rate and comment on files. If you have any concerns, feel free to contact me at firstname.lastname@example.org.