subroutine getgsst(lusst,mxlon,mxlat,iyearg,imong,idayg,ifound,
     +                   glon1,glon2,dlong,nlong,
     +                   glat1,glat2,dlatg,nlatg,sstll)
c
c     This routine reads the global weekly Reynold's SST file from unit lusst and
c     puts the results in the array sstll. The date and grid parameters 
c     are also returned. If there is an error reading the file, ifound 
c     is set to zero.
c
c     The parameters mxlon and mxlat must be the same as those in the
c     calling routine. 
c
c     This routine can also be used to get the daily SST data on a 
c     global or regional grid.
c
      dimension sstll(mxlon,mxlat)
c
c     Ready the header line
      read(lusst,*,err=1000) iyearg,idm,itime,glon1,glon2,dlong,
     +                                        glat1,glat2,dlatg,idum
c
      imong = idm/100
      idayg = idm - 100*imong
c
      nlong = 1 + ifix(0.001 + (glon2-glon1)/dlong)
      nlatg = 1 + ifix(0.001 + (glat2-glat1)/dlatg)
c
c     Read the data lines
      do j=1,nlatg
      do i=1,nlong
         read(lusst,*,err=1000,end=1000) xlon,xlat,sstll(i,j)
      enddo
      enddo
c
      ifound=1
      return
c
 1000 continue
      ifound=0
      return
c
      end