gtk_tree_view_column_set_sort_column_id(col, DIVE_NITROX);
gtk_tree_view_column_pack_start(col, renderer, FALSE);
gtk_tree_view_column_add_attribute(col, renderer, "text", DIVE_NITROXSTR);
gtk_tree_view_column_set_sort_column_id(col, DIVE_NITROX);
gtk_tree_view_column_pack_start(col, renderer, FALSE);
gtk_tree_view_column_add_attribute(col, renderer, "text", DIVE_NITROXSTR);