gtk_menu_attach (GTK_MENU (obj->column_popup_menu), insert_variable, 0, 1, i, i + 1); ++i;
gtk_menu_attach (GTK_MENU (obj->column_popup_menu), clear_variables, 0, 1, i, i + 1); ++i;
gtk_menu_attach (GTK_MENU (obj->column_popup_menu), gtk_separator_menu_item_new (), 0, 1, i, i + 1); ++i;
gtk_menu_attach (GTK_MENU (obj->column_popup_menu), insert_variable, 0, 1, i, i + 1); ++i;
gtk_menu_attach (GTK_MENU (obj->column_popup_menu), clear_variables, 0, 1, i, i + 1); ++i;
gtk_menu_attach (GTK_MENU (obj->column_popup_menu), gtk_separator_menu_item_new (), 0, 1, i, i + 1); ++i;