Facebook SDK 3.5 is not working on ios 5.1 - iphone

Question

I have implemented facebook in my application. It is working on ios 6 but when it os run on ios5 it is giving error as " The operation coudn't be completed (com.facebook.sdk error 2)"
Following is my code
- (void)postStatusUpdateClick:(NSString *)url:(UIViewController*)view:(UIView*)view1
{
NSString *shareString=[NSString stringWithFormat:#"Check out this great deal at %#",url];
NSURL *urlToShare = [NSURL URLWithString:url];
FBAppCall *appCall = [FBDialogs presentShareDialogWithLink:urlToShare
name:#"Hello Facebook"
caption:nil
description:shareString
picture:nil
clientState:nil
handler:^(FBAppCall *call, NSDictionary *results, NSError *error) {
if (error) {
NSLog(#"Error: %#", error.description);
} else {
NSLog(#"Success!");
}
}];
if (!appCall) {
// Next try to post using Facebook's iOS6 integration
BOOL displayedNativeDialog = [FBDialogs presentOSIntegratedShareDialogModallyFrom:view
initialText:shareString
image:nil
url:urlToShare
handler:^(FBOSIntegratedShareDialogResult result, NSError *error) {
if (error && [error code] == 7) {
return;
} NSString *alertText = #"";
if (error) {
alertText = [NSString stringWithFormat:
#"error: domain = %#, code = %d",
error.domain, error.code];
} else if (result == FBNativeDialogResultSucceeded) {
alertText = #"Posted successfully.";
}
if (![alertText isEqualToString:#""]) {
// Show the result in an alert
[[[UIAlertView alloc] initWithTitle:#"Result"
message:alertText
delegate:self
cancelButtonTitle:#"OK!"
otherButtonTitles:nil]
show];
}
}];
if (!displayedNativeDialog) {
// Lastly, fall back on a request for permissions and a direct post using the Graph API
[self performPublishAction:^{
[FBRequestConnection startForPostStatusUpdate:shareString
completionHandler:^(FBRequestConnection *connection, id result, NSError *error) {
[self showAlert:#"jhj" result:result error:error];
}];
}];
}
}
}
- (void)showAlert:(NSString *)message
result:(id)result
error:(NSError *)error {
NSString *alertMsg;
NSString *alertTitle;
if (error) {
alertTitle = #"Error";
if (error.fberrorShouldNotifyUser ||
error.fberrorCategory == FBErrorCategoryPermissions ||
error.fberrorCategory == FBErrorCategoryAuthenticationReopenSession) {
alertMsg = error.fberrorUserMessage;
} else {
alertMsg = #"Operation failed due to a connection problem, retry later.";
}
} else {
NSDictionary *resultDict = (NSDictionary *)result;
alertMsg = [NSString stringWithFormat:#"Successfully posted '%#'.", message];
NSString *postId = [resultDict valueForKey:#"id"];
if (!postId) {
postId = [resultDict valueForKey:#"postId"];
}
if (postId) {
alertMsg = [NSString stringWithFormat:#"%#\nPost ID: %#", alertMsg, postId];
}
alertTitle = #"Success";
}
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:alertTitle
message:alertMsg
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alertView show];
}
- (void) performPublishAction:(void (^)(void)) action {
if ([[FBSession activeSession]isOpen]) {
/*
* if the current session has no publish permission we need to reauthorize
*/
if ([[[FBSession activeSession]permissions]indexOfObject:#"publish_actions"] == NSNotFound) {
[[FBSession activeSession] requestNewPublishPermissions:[NSArray arrayWithObject:#"publish_action"] defaultAudience:FBSessionDefaultAudienceFriends
completionHandler:^(FBSession *session,NSError *error){
if (!error) {
action();
}
}];
}else{
//[self publishStory];
action();
}
}else{
/*
* open a new session with publish permission
*/
[FBSession openActiveSessionWithPublishPermissions:[NSArray arrayWithObject:#"publish_actions"]
defaultAudience:FBSessionDefaultAudienceFriends
allowLoginUI:YES
completionHandler:^(FBSession *session,
FBSessionState status,
NSError *error) {
// if login fails for any reason, we alert
if (error) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error"
message:error.localizedDescription
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alert show];
}
}
When I Debugged the code it is showing FBSessionStateClosedLoginFailed