Perfect square or not.(FUNCTION)

DECLARE FUNCTION PERFECT (S)
CLS
INPUT "ENTER ANY NUMBER"; N
S = SQR(N)
PR = PERFECT (S)
IF PR = S THEN
PRINT "PERFECT SQUARE"
ELSE
PRINT "NOT PERFECT SQUARE"
END IF
END

FUNCTION PERFECT (S)
PERFECT = INT (S)
END FUNCTION