i am executing the following code to logout of faceboook from my iphone app if ([mFacebook isSessionValid]) { [mFacebook logout]; } this code runs successfully and the delegate is called after this in which i am clearing the access token - (void)fbDidLogout { NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; [defaults removeObjectForKey:@"FBAccessTokenKey"]; [defaults removeObjectForKey:@"FBExpirationDateKey"]; [defaults synchronize]; } but when i again login to facebook, it does not ask for username and password. Can someone please suggest me what wrong am i doing?? Thanks in advance.