UITableView Transparent BackGround

I got this code :

开发者_高级运维UIViewController *nextQuestionView = [[QuizzQuestionViewController alloc]init];
    nextQuestionView.view.backgroundColor=[UIColor colorWithRed:0.44 green:0.44 blue:0.41 alpha:1];
    [self.navigationController pushViewController:nextQuestionView animated:YES];
    NSLog(@"gotonextQuestion");
    [nextQuestionView newQuestion];
    [nextQuestionView release];

And i want to remove the black corner.

Thanks.