anchor.diff:  %%%---------------------------------------------------------------------
   %%% END of functions used to create the grid.
   %%%---------------------------------------------------------------------
  +
  +
  +%%======================================================================
  +%% Function:
  +%%
  +%% Return Value:
  +%%
  +%% Description:
  +%%
  +%% Parameters:
  +%%======================================================================
  +
  +
  +safe_nthtail(_, []) -> [];
  +safe_nthtail(1, [_|T]) -> T;
  +safe_nthtail(N, [_|T]) when N > 1 ->
  +    safe_nthtail(N - 1, T);
  +safe_nthtail(0, L) when is_list(L) -> L.
  
positive.code: 	check_nof_cols(ColsShown, (NofColsShown - NofCols), ColFrameIds, ColIds, 
  		       RowIds, NofRows, RowHeight, FgColor, BgColor ),
  
      clear_fields(lists:nthtail(NofColsShown, NewColIds), 
  		 lists:nthtail(NofRowsShown, NewRowIds)),
  
      RowsToUpdate = lists:sublist(NewRowIds, NofRowsShown),
  
  
negative.code:     if 
  	NecessaryNofVirtualCols > NofVirtualCols ->
  	    TailNo = NofVirtualCols - FirstColShown + 1,   % Always >= 0 !!!
  	    NewColWidths ++ safe_nthtail(TailNo, ColsShown);
  	true ->
  	    NewColWidths
      end.
  