i use ubuntu 10.10

I want to change my gdm login to kdm login screen,,
i've tried this thread http://ubuntuforums.org/showthread.php?t=1329744
but after i reboot it's success and i loging in using kdm login screen, but after i login i've got nothing but a console ,i mean there are really black and leave me with just one console...can you help me??

thanks a lot sir