Changing side margins in specific mode changes side margins for all buffers

[hack writer <GNU@bookhacker.org>]

Hi everyone,

I use

(add-hook 'window-configuration-change-hook (lambda () (set-window-margins
(car (get-buffer-window-list (current-buffer) nil t)) 29 29)))

to set side margins in a specific emacs mode. But when I open further
buffers, no matter what mode, all buffers use the same side margins. How I
can achieve, that only my specific mode buffers use side margins but all
other buffers not?

(add-hook 'window-configuration-change-hook (lambda () (set-window-margins
(car (get-buffer-window-list (current-buffer) nil t)) 29 29))
'make-it-local)

didn't work.

Regards

hack