* not in table output
  if tabmode = c_tabmode_contents.
    err_comp ssf_err_next_page_in_table 'E' 192
             space space space space.
  endif.

function ssfcomp_set_next_page.
*"----------------------------------------------------------------------
*"*"Lokale Schnittstelle:
*"  IMPORTING
*"     VALUE(I_NEXT_PAGE) TYPE  SSFKEYNAME OPTIONAL
*"  EXCEPTIONS
*"      ERROR
*"----------------------------------------------------------------------
data: l_next_page type ssfkeyname,
      l_dummy     type tdtltype.

* check if document has been started
  if ssfcstat-tdstarted = c_false or ssfcstat-tdopen = c_false.
    err_comp ssf_err_next_page_unstarted 'A' 164 i_next_page
             space space space.
  endif.

* only valid in main window
  if docentry-tdwtype <> c_wtype_main.
    err_comp ssf_err_next_page_non_main 'E' 165 docentry-tdwtype
             space space space.
  endif.

** not in table output
*  if tabmode = c_tabmode_contents.
*    err_comp ssf_err_next_page_in_table 'E' 192
*             space space space space.
*  endif.

* output closed in main window
  if xsfop-xsf = c_false and document_index = 0.
    err_comp ssf_err_no_more_main_window 'A' 203
             space space space space.
  endif.

  if not i_next_page is initial.
*   page valid?
    read table document with key tdpage = i_next_page
                        transporting no fields.
    if sy-subrc <> 0.
      err_comp ssf_err_next_page_unknown 'E' 166 i_next_page
               space space space.
    endif.
    l_next_page = i_next_page.
  else.
*   choose default next page, may be initial (!)
    l_next_page = docentry-tdnextpage.
  endif.

  perform xsf_new_page using l_next_page.

  if tabmode = c_tabmode_contents.
*   no interrupt in protected area
    perform tab_handle_interrupt using c_tab_interrupt_new_row
                                       l_dummy c_false.
  else.
*   force page break
    perform force_page_break using l_next_page.
  endif.

  perform xsf_set_main.

endfunction.