If you want to delete your facebook account permanently you should go to:
http://www.facebook.com/help/contact.php?show_form=delete_account
Log in if not already logged in > Click Submit > Okay > DO NOT access your account within 14 days or it will be activated again.
See below/
1. Click Submit
2. Click OK – Do not access your account for 14 days
For the future planning this blog is very useful and supportive to php programmer.
OMG! It is so easy!
Thanks you!