Calling a subroutine
During program development it’s important to notice which of its parts can be reused and, based on that fact, should create subroutines that will be called within the main program. Subroutines can be functions and procedures. We use the functions by specifying the variable name, followed by equality sign, and then the name of the function with the arguments. We invoke the procedures using the Call command, after which we specify the procedure name with the arguments.