C===============================================================================
      SUBROUTINE CTVMsv (WHICH, WHERE)
C===============================================================================
C  Silly, trivial little routine to save, interchange, or restore the results
C  of a CTVMFT fit.
C  WHICH < 0   Copy the CTVMFT fit results to local storage for preservation
C        = 0   Interchange the stored fit result with that in the CTVMFT common
C        > 0   Overwrite the CTVMFT fit result with the stored result
C  WHERE       An index specifying where to store or where to extract fit
C              information.
C-------------------------------------------------------------------------------
        IMPLICIT NONE
#include <Stntuple/fit/ctvmft.inc>
      INTEGER    IJKLMN
      PARAMETER (IJKLMN = MAXDIM*(MAXDIM+1))
      INTEGER WHICH, WHERE
      INTEGER I
      INTEGER SAVRSL(UDIM,4), SLUSH(UDIM)
      DOUBLE PRECISION UMAT(MAXDIM*(MAXDIM+1),4),
     >                 BLUSH(MAXDIM*(MAXDIM+1))
      REAL SCREAM, MINUS, ZERO
      SAVE SAVRSL, UMAT, MINUS,ZERO
      DATA MINUS /-1.0/, ZERO /0.0/
C============ save or restore existing constrained fit results ===============
      IF (WHERE.LE.0 .OR. WHERE.GT.4) THEN
        PRINT 1000, WHERE
 1000   FORMAT (' CTVMsave; nonsense WHERE!' )
        SCREAM = SQRT(MINUS) / ZERO
        return
      END IF
      IF (WHICH) 10,20,30
C save the existing fit from CTVMFq,r
   10 CONTINUE                       
      DO I=1,UDIM
        SAVRSL(I,WHERE) = UVWXYZ(I)
      END DO
      DO I=1,IJKLMN
        UMAT(I,WHERE) = VMAT(I,1)
      END DO
      GO TO 100
C flip the stored fit with that in CTVMFq,r
   20 CONTINUE                       
      DO I=1,UDIM
        SLUSH (I) = SAVRSL(I,WHERE)
        SAVRSL(I,WHERE) = UVWXYZ(I)
        UVWXYZ(I) = SLUSH (I)
      END DO
      DO I=1,IJKLMN
        BLUSH(I)  = UMAT(I,WHERE)
        UMAT (I,WHERE)  = VMAT(I,1)
        VMAT(I,1) = BLUSH(I)
      END DO
      GO TO 100
C restore the CTVMFq,r contents
   30 CONTINUE                        
      DO I=1,UDIM
        UVWXYZ(I) = SAVRSL(I,WHERE)
      END DO
      DO I=1,IJKLMN
        VMAT(I,1) = UMAT(I,WHERE)
      END DO
  100 CONTINUE
      RETURN
      END