SUBROUTINE PRSENT(R,T,FP,FS)
C      ============================
C
C      interpolates pressure and entropy from tables
C
       INCLUDE 'IMPLIC.FOR'
       COMMON/THERM/SL(330,100),PL(330,100)
       COMMON/TABLTD/R1,R2,T1,T2,T12,T22,INDEX
       common/tdedge/redge,pedge(100),sedge(100),cvedge(100),
     &               cpedge(100),gammaedge(100),tedge(100)
       common/tdflag/JON
C
       JON=0
       RL = DLOG10(R) 
       ALPHA=T1+(RL-R1)/(R2-R1)*(T12-T1)
       BETA=T2-T1+((T22-T12)-(T2-T1))*(RL-R1)/(R2-R1)
       QL = (DLOG10(T) - ALPHA)/BETA
       DELTA=(RL-R1)/(R2-R1)*FLOAT(INDEX-1)
       JR = 1 + IDINT(DELTA)
       JQ = 1 + IDINT(99.*QL)
       IF(JR.LT.2) GO TO 300
       IF(JR.GT.(INDEX-1)) GO TO 300
       IF(JQ.LT.2) GO TO 300
       IF(JQ.GT.99) GO TO 300
       P = DELTA - (JR-1)
       Q = 99.*QL - (JQ-1)
C        interpolate:
       FS = 0.5D0*Q*(Q-1.D0)*SL(JR,JQ-1)
     1  + 0.5D0*P*(P-1.D0)*SL(JR-1,JQ)
     2  + (1.D0+P*Q-P*P-Q*Q)*SL(JR,JQ)
     3  + 0.5D0*P*(P-2.D0*Q+1.D0)*SL(JR+1,JQ)
     4  + 0.5D0*Q*(Q-2.D0*P+1.D0)*SL(JR,JQ+1)
     5  + P*Q*SL(JR+1,JQ+1)
        FS = 10.D0**FS
C
       FP = 0.5D0*Q*(Q-1.D0)*PL(JR,JQ-1)
     1  + 0.5D0*P*(P-1.D0)*PL(JR-1,JQ)
     2  + (1.D0+P*Q-P*P-Q*Q)*PL(JR,JQ)
     3  + 0.5D0*P*(P-2.D0*Q+1.D0)*PL(JR+1,JQ)
     4  + 0.5D0*Q*(Q-2.D0*P+1.D0)*PL(JR,JQ+1)
     5  + P*Q*PL(JR+1,JQ+1)
        FP = 10.D0**FP
      RETURN
C
C       off the table
C
300    CONTINUE
C
       write(60,*) ' Off the table!'
C
       JQ = min(98,max(JQ, 2))
       JON = JQ
       FP = pedge(JQ)*R*T/(redge*tedge(JQ))
       FS = sedge(JQ) + 1.d0/(gammaedge(JQ)-1.d0)*
     &      dlog(FP/pedge(JQ)*(redge/R)**gammaedge(JQ))
       write(60,*) JQ, R, T, FP, FS
C
       RETURN
       END