Detect someone who defriend you on facebook

How to detect someone who defriend you from their facebook friendlist? (for Mozilla Firefox user)
  1. Open Mozilla Firefox
  2. Type this address http://addons.mozzila.org/en-US/firefox
  3. type Greasemonkey in search coulumn, then press ENTER
  4. In the Greasemonkey, click Add to firefox
  5. Software Installation window appears, click Install Now button
  6. After installation is complete, click Restart Firefox
  7. http://userscripts.org/scripts/show/58852 type the address in the url column
  8. click Install on the Finder for up Unfriend
  9. Click the Install button on the window Greasemonkey Installation
 10. go to facebook page and log in to your account
 11. Welcome page of Unfriend appears, click Close
 12. select menu Unfriend on the left side menu, and you will see your friend who remove you from their friendlist