How do I hide my wall from non-friends in new facebook privacy option?

[Atul gandhi]

go to http://www.facebook.com/settings/?tab=privacy
under default privacy tab chose friends
this will make your future posts visible only to your s
for earlier messages
go to the "limit the audience for past posts" on d same page
on its right side u will see a link called "manage post visibility"
then click on limit old posts
and then confirm
but remember u can't undo these changes