[SIGSEGV when test mod] is there any exmaple code?

[Novice-me]

when i test the mod with following code

      program main
      use tecplotwrite
      parameter(ni=10,nj=10)
      Real*8 x(ni,nj),y(ni,nj)
      Real*8 u(ni,nj),v(ni,nj)
      type(tecplotDataTemplate) :: data2Write
      
      do i = 1,ni
      do j = 1,nj
         x(i,j) = dble(i-1)/dble(ni-1)
         y(i,j) = dble(j-1)/dble(nj-1)

         u(i,j) = dble(i-1)
         v(i,j) = dble(j-1)
      enddo
      enddo
      data2Write%inunit = 10
      data2Write%datatitle = 'testmod.plt'
      data2Write%IMax = ni
      data2Write%JMax = nj
      data2Write%KMax = 1
      data2Write%Nvars = 4
      do i = 1,ni
      do j = 1,nj
            !------------ bug area ----------!
            data2Write%data(i,j,1,1) = x(i,j)
            data2Write%data(i,j,1,2) = y(i,j)
            data2Write%data(i,j,1,3) = u(i,j)
            data2Write%data(i,j,1,4) = v(i,j)
            !------------ bug area ----------!
      end do
      end do
      write(*,*) 'before Writing tecplot binary file .. '
      call tecplot_write_binary(data2Write) 
      stop
      end

how can i define the data for writing with data2Write%data, is there any exmaple code?