C                       Data_flow.f
C      	  Note that the incorrect statements and their corrections are indicated by comments.
	  SUBROUTINE DOLS(PSF, LCRT, D1, D2,COST)
          PI = 3.1416
          IF(LCRT.NE.1)GO TO 10
          COST = PSF*AREAR(D1,D2)
          RETURN
   10     IF(LCRT.NE.2) GO TO 20
          COST = PSF*AREAC(P, D1)
          RETURN
   20     COST = PSF*AREAT(D1,D2)
          RETURN
          END
          FUNCTION AREAR(X,Y)
          AREAR = X*Y
          RETURN
          END
          FUNCTION AREAC(PI, R)
          AREAC = PI*R**2
          RETURN
          END
          FUNCTION AREAT(B,H)
          AREAT = 0.5*B*H
          RETURN
          END
C         A misspelling of PI (or P) is present.