installing Window Manager

["spider" <bziku@spider.ds11.agh.edu.pl>]

i wanted to run SAWMILL as window manager (im not using ximian so i couldnt
install sawfish) on gdm.

i did:
    update-alternatives --config x-window-manager

and then i chose SAWMILL as the window manager from the list.

BUT:
i thought i should edit a file, particularly .xinitrc or .xsession...
i have ~/.xsession file and it has only one line: exec gnome-session.

anyway i just want to know whether i did the right thing to have a window
manager or i should have done it in a different way/

thanks.