title: Login Logout issue with facebook iOS sdk
body: <p>We have got sruck in the iOS facebook login logout issue. When I login to facebook using my application it will prompt for user permission with 'login' and 'cancel' button.  But this screen appears only on the very first time. ie Once we logged in using safari or the app and even if we logged out from facebook , application the screen prompting for user permission displays only an 'ok' button. It doesnt allow to sign in as a different user. Why the screen with 'login' and 'cancel' button not displaying each time the application launches? I tried by deleting cookies and removing NSUserDefaults but no luck.</p>
  
  <p>The problem is after logout, I am unable to login to the facebook as another user. It still shows as the same user.</p>
  
  <p>I am calling the below logout function in sdk</p>
  
  <pre><code>(void)logout:(id&lt;FBSessionDelegate&gt;)delegate {
  
    self.sessionDelegate = delegate;
   [_accessToken release];
   _accessToken = nil;
   [_expirationDate release];
   _expirationDate = nil;
  
   NSHTTPCookieStorage* cookies = [NSHTTPCookieStorage sharedHTTPCookieStorage];
   NSArray* facebookCookies = [cookies cookiesForURL:
   [NSURL URLWithString:@"http://login.facebook.com"]];
   for (NSHTTPCookie* cookie in facebookCookies) {
     [cookies deleteCookie:cookie];
   }
  
  if ([self.sessionDelegate respondsToSelector:@selector(fbDidLogout)]) {
    [_sessionDelegate fbDidLogout];
  }
  }
  </code></pre>
  
  <p>Also in fbDidLogout delegate function I removed all NSUserDefaults objects </p>
  
  <pre><code>NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
  if ([defaults objectForKey:@"FBAccessTokenKey"]) {
      [defaults removeObjectForKey:@"FBAccessTokenKey"];
      [defaults removeObjectForKey:@"FBExpirationDateKey"];
      [defaults synchronize];
  }
  </code></pre>
  
  <p>regrds
  Shihab</p>