Twitter account access

-(void)onTwitterButton:(id)sender
{
    if ([TWTweetComposeViewController canSendTweet]) {
        ACAccountStore *account = [[ACAccountStore alloc] init];
        ACAccountType *accountType = [account accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierTwitter];
        [HUD show:YES]; 
        [account requestAccessToAccountsWithType:accountType withCompletionHandler:^(BOOL granted, NSError *error){
            dispatch_async(dispatch_get_main_queue(), ^{
                if (granted){
              
                    MSTwitterSelectorViewController *TWSelector =
                    [[MSTwitterSelectorViewController alloc]initWithAccounts:[account accountsWithAccountType:accountType]];
                    [TWSelector setDelegate:self];
                    UINavigationController *twitterNC = [[UINavigationController alloc]initWithRootViewController:TWSelector];
                    [self presentModalViewController:twitterNC animated:YES];
                }
                else{
                    [self displayTwitterAccessErrorMessage];
                    [HUD hide:YES];
                }

            });}];
    }
    else{
        [self displayPleaseRegisterTwitterMessage]; 
    }
}