Just 1 will work as well. EXIT before the subroutines. Your subroutine, or function. This is not required, but a good idea. Using it means that variables are not shared with the main part of the program.
Commas separate the items.
The parentheses around the things being compared are not needed. Nothing wrong with that style. The two commas - the last one is for continuation. The first one is needed to separate the items being passed. A subroutine or function always ends with a return If you put something after the return it is passed back to the calling statement.