postscript(Data) :-
    new(D, dialog('Print destination')),
    send(D, append, new(T, menu(destination, marked))),
    send_list(T, append, [printer, file]),
    send(T, layout, horizontal),
    send(D, append, new(A, text_item(printer_name, 'PostScript'))),
    send(T, message,
         if(T?selection == printer,
            message(A, label, ?(A, label_name, printer_name)),
            message(A, label, ?(A, label_name, file_name)))),
    send(D, append,
         button(ok, and(message(@prolog, print_postscript,
                                T?selection, A?selection, Data),
                        message(D, destroy)))),
    send(D, append,
         button(cancel, message(D, destroy))),
    send(D, open).

print_postscript(printer, Address, Data) :-
    !,
    new(F, file),
    send(F, open, write),
    send(F, append, Data),
    send(F, close),
    get(F, name, TmpFile),
    get(string('lpr -P%s %s &', Address, TmpFile),
        value, Command),
    unix(shell(Command)).
print_postscript(file, Address, Data) :-
    new(F, file(Address)),
    send(F, open, write),
    send(F, append, Data),
    send(F, close).