Display greatsest among three numbers.(SUB)

DECLARE SUB GREAT (A,B,C)

CLS

INPUT"ENTER ANY NO. ";A
INPUT"ENTER ANY NO."; B
INPUT"ENTER ANY NO.";C

CALL GREAT(A,B,C)

END

SUB GREAT (A,B,C)

IF A > B AND A>C THEN

PRINT"THE GREATEST NO. IS";A

ELSE IF B>A AND B>A THEN

PRINT"THE GREATEST NO. I S";B

ELSE

PRINT"THE GREATEST NO IS";C

END IF 

END SUB