Area of 4 walls(sub)

DECLARE SUB AR(L,B,H)
CLS
INPUT"ENTER LENGTH";L
INPUT'"ENTER BREADTH";B
INPUT"ENTER HEIGHT";H
CALL AR(L,B,H)
END

SUB AR(L,B,H)
ARE=2*H*(L+B)
PRINT"AREA OF 4 WALLS =";ARE
END SUB