Help configure Xorg

Sat Jun 10 07:43:46 PDT 2006

Hi all,
I just left Xfree86 to use Xorg on my ibook g4 (ppc), mainly for kde.
I missed how to configure xorg. Double clic on the Xdarwin.app icon 
(the one created by xorg) will launch Xorg but typing "startx" on the 
terminal will launch the xfree86 version of Xdarwin. How can I get 
rid of that?
I notice that I have no xorg.conf file in my /etc/x11 folder. I tryed 
to run "Xorg -configure" but it doesn't work.
Well, to resume I have both xorg and xfree86 version of xdarwin 
installed, but I don't understand, when kde is launched, which config 
file are used and how to set up Xorg to launch with the startx 
command (instead of xfree86).
Can someone help me to configure all that?
Thank you in advance for help.