this is my i am gitting error why any one tell me they can give me error

NSMutableDictionary *inputData = [NSMutableDictionary dictionaryWithObjectsAndKeys:[self.usertext text], @"username", [self.passwordtext text], @"password", nil]; NSData *jsonData = [NSJSONSerialization dataWithJSONObject:inputData options:0 error:nil]; NSString *json = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding]; NSDictionary *dict = @{@"body":json}; NSLog(@"JSOND: %@", dict); NSLog(@"JSON: %@", json); // Create a Request with the given URL AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager]; manager.responseSerializer = [AFJSONResponseSerializer serializer]; [manager.requestSerializer setValue:@"application/json" forHTTPHeaderField:@"Accept"]; [manager.requestSerializer setValue:@"application/json" forHTTPHeaderField:@"Content-Type"]; [manager.requestSerializer setValue:@"bearer null" forHTTPHeaderField:@"Authorization"];

        [manager POST:@"http://ift.tt/1OSE5TF" parameters:dict success:^
         (AFHTTPRequestOperation *operation, id responseObject)
         {
             NSLog(@"operation: %@", operation);
             NSLog(@"Response: %@", responseObject);
            }
              failure:^(AFHTTPRequestOperation *operation, NSError *error) {
            NSString *myString = [[NSString alloc] initWithData:operation.request.HTTPBody encoding:NSUTF8StringEncoding];
            NSLog(@"Error: %@", myString);
        }];