subroutine adder(id)
      integer id
      real hxy
      external hxy
      integer i,j
      real x,y
      real sumi,sumo
      sumi=0
      sumo=0
      do i=1,640
       x=(i-0.5)/640
       do j=1,480
         y=(j-0.5)/480
         if ((x.le.0.129).or.(x.ge.0.8095).or.(y.lt.0.107)) then
           sumo=sumo+hxy(id,x,y)
         else
           sumi=sumi+hxy(id,x,y)
         endif
       enddo
      enddo
      print *, 'inside sum is',sumi
      print *, 'outside sum is',sumo
      end