title: Add multiple UIWindow
body: <p>I am adding a new UIWIndow over another to display a view, but it is not showing anything and the screen just gets a little blurred. Here is the code:</p>
  
  <pre><code>UIWindow* topWindow = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
  [topWindow setWindowLevel:UIWindowLevelNormal];
  
  CGFloat statusBarHeight = [UIApplication sharedApplication].statusBarFrame.size.height;
  
  UIViewController* viewController = [[UIViewController alloc] init];
  UIView* overlay = [[UIView alloc] initWithFrame:CGRectMake(0, -statusBarHeight,   viewController.view.frame.size.width, statusBarHeight - 1)];
  [overlay setAutoresizingMask:UIViewAutoresizingFlexibleWidth];
  [overlay setBackgroundColor:[UIColor whiteColor]];
  [viewController.view addSubview:overlay];
  [topWindow setRootViewController:viewController];
  
  [topWindow setHidden:NO];
  [topWindow setUserInteractionEnabled:NO];
  [topWindow makeKeyAndVisible];
  
  viewController = nil;
  
  overlay = nil;
  </code></pre>
  
  <p>What am I doing wrong?</p>