Stop Facebook from Auto Login

Hi Vibe, I have successfully integrated facebook login and able to login & logout. BUT i found out: step 1. logout step 2. then click Facebook login again (from top bar) step 3. automatically login step 4. logout again step 5. check who's online (user still online - where actually already logout) step 6. check facebook.com --> user still login step 7. logout from facebook.com --> user logout How to make it totally logout? because if user access from public computer, then he/she thinks already logged out from site, but actually NOT (only seem out). Then another people use the computer, may accidentally access his/her facebook, which is BAD.. Please help vibe. Thanks!