Program to change UC to LC & LC to UC...

IDENTIFICATION DIVISION.
PROGRAM-ID. PROG001.
ENVIRONMENT DIVISION.
DATA DIVISION.
WORKING-STORAGE SECTION.
77 CASE                         PIC A(6) VALUE 'ABcdEF'.
77 LCASE                      PIC A(6).
77 UCASE                      PIC A(6).
PROCEDURE DIVISION.
MOVE FUNCTION LOWER-CASE ( CASE ) TO LCASE.
DISPLAY LCASE.
MOVE FUNCTION UPPER-CASE ( CASE ) TO UCASE.
DISPLAY UCASE.
STOP RUN.