subroutine upbox (l,j,ipdx,nedge,fkm,n,box)
c
c=======================================================================
c                                                                    ===
c  This routine determines if the given index is valid for averaging ===
c  coastal boundary values.                                          ===
c                                                                    ===
c=======================================================================
c
c-----------------------------------------------------------------------
c  Define global data.
c-----------------------------------------------------------------------
c
#include <cdefs.h>
#include <pconst.h>
c
c-----------------------------------------------------------------------
c  Define local data.
c-----------------------------------------------------------------------
c
      integer box,i,j,l,n,nedge
      integer ipdx(nedge)
      FLOAT
     *      fkm(n)
c
c=======================================================================
c  Begin executable code
c=======================================================================
c
      if(fkm(j).gt.c0) then
         do 10 i=1,nedge
            if(ipdx(i).eq.j) goto 20
  10     continue
         box=j
         l=l+1
  20     continue
      endif
c
      return
      end