Positive or negative.(SUB)

DECLARE SUB CHECK(N)
CLS
INPUT"ENTER ANY NO.";N
CALL CHECK(N$)
END

SUB CHECK(N)
IF N > 0 THEN
PRINT"POSITIVE NO."
ELSE IF N  < 0 THEN
PRINT"NEGATIVE NO."
ELSE
PRINT"ZERO"
END IF
END SUB