how to change GNOME to KDE desktop?

Hi all, good evening,

Anyone know how to start with the KDE desktop by default?

I am using GDM and i will install KDE and GNOME for more choice, but with GDM the default desktop is GNOME.

I have configured /etc/sysconfig/desktop:
DESKTOP="KDE"
DISPLAYMANAGER="GNOME"

In my kickstart File i have a desktop directive:
xconfig --defaultdesktop=KDE --startxonboot


//

yum groupinstall "KDE Desktop"

yum groupinstall "KDE Desktop" 

The choice appears when you choose the user and enter the password, at the bottom of the screen.

but the desfault desktop is always GNOME

Thanks if you have an idea