Possible Duplicate:
How do I change the default session for LightDM when using auto-logins?
I've installed gnome-shell on Ubuntu 11.10 from official repository. But after the choosing GNOME session at the greeter window, login in gnome-shell and after this rebooting, it doesn't boot automaticaly to gnome-shell(as was before with unity session). It just stops at the greeter window with option to type password and choose the session. How to make autologin to gnome-shell?