anchor.diff:        mxval = -99999
         user = 0
         p = 0
  +      z = 0
   
         narg = iargc()
         if (narg.eq.0) call usage()
  
positive.code:       write (*,*)
       1 '  -max [MXVAL] (Default undefined) maximum value in the list'
        write (*,*)
       1 '  -h/-?        Online help (this screen)'
        write (*,*) ''
        
  
negative.code:       PARAMETER (NMAX=1000)
        INTEGER ct(NMAX)
        INTEGER mnval,mxval,dumval,mnsrch,mxsrch,val,diff
        INTEGER i,istart,iend,itmin,itmax,j,niter,user,p,z
        
        mnsrch = 0
        mxsrch = 0
  
        call gcmdln(ifile,ofile,mnval,mxval,z,p,user)
        open (unit=12,file=ofile,status='unknown')
        if (mnval.eq.-99999) mnsrch = 1
        if (mxval.eq.-99999) mxsrch = 1
  