Cannot post to twitter with an iPhone app with no errors

I am using at my iPhone app with this code but I can not see the post on my twitter. I am not getting an error back.

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:
                                    [NSURL URLWithString:@"http://username:password@twitter.com/statuses/update.xml"] 
                                                           cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:15.0];
    // The text to post
    NSString *msg = @"testing";
    
    // Set the HTTP request method
    [request setHTTPMethod:@"POST"];
    
    [request setHTTPBody:[[NSString stringWithFormat:@"status=%@", msg] 
                          dataUsingEncoding:NSASCIIStringEncoding]];
    
    NSURLResponse *response;
    NSError *error;
    
    if ([NSURLConnection sendSynchronousRequest:request 
                              returningResponse:&response error:&error] != nil)
        NSLog(@"Your Poem posted to Twitter successful开发者_如何学编程ly.");
    else 
        NSLog(@"Could not post to Twitter");

Can anyone tell me what is wrong?

Basic authentication was removed in August. You must now use OAuth. See https://dev.twitter.com/ for details.

Edit: There are several libraries to do this. I have been using this iPhone ready implementation of oauthconsumer: http://github.com/jdg/oauthconsumer

Twitter disabled basic auth recently, you must use OAuth instead.