iphone beginner : Cannot figure out where the leak is - iphone

Question

I am trying to get my hands on some iphone development. To try to better understand things, I'm going first without IB.
I managed to build a basic app that displays some text. No big deal, until I ran it through Instruments. It shows me some leaks and I cannot understand them.
Any help on this would be greatly appreciated.
MyAppDelegate.h
#interface MyAppDelegate : NSObject <UIApplicationDelegate> {
UIWindow *window;
MyViewController *viewController;
}
#property (nonatomic, retain) IBOutlet UIWindow *window;
#property (nonatomic, retain) MyViewController *viewController;
#end
MyAppDelegate.m
#implementation MyAppDelegate
#synthesize window;
#synthesize viewController;
- (void)applicationDidFinishLaunching:(UIApplication *)application {
// NEXT LINE LEAKS
[window addSubview:viewController.view];
[window makeKeyAndVisible];
}
- (void)dealloc {
[viewController release];
[window release];
[super dealloc];
}
#end
MyViewController.h
#interface MyViewController : UIViewController {
UILabel *firstMessage;
}
MyViewController.m
-(void)loadView {
// Background
CGRect mainFrame = [[UIScreen mainScreen] applicationFrame];
UIView *contentView = [[UIView alloc] initWithFrame:mainFrame];
contentView.backgroundColor = [UIColor blackColor];
self.view = contentView;
[contentView release];
// Add UILabel
// NEXT LINE LEAKS
firstMessage = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, 30)];
firstMessage.font = [UIFont fontWithName:#"Helvetica" size:16];
firstMessage.textColor = [UIColor whiteColor];
firstMessage.backgroundColor = [UIColor blackColor];
[self.view addSubview:firstMessage];
[firstMessage release];
}
-(void) viewDidLoad {
NSString * msg;
msg=[[NSString alloc] initWithFormat:#"stuff here"];
firstMessage.text=msg;
[msg release];
}
-(void)dealloc {
[firstMessage release];
[super dealloc];
}

Answer 1

Try using #property (nonatomic, retain) UILabel* firstMessage in your header, #synthesize firstMessage in your implementation and then release your firstMessage object in the dealloc method.

Answer 2

Try not to release your firstMessage in loadView. Only release it in your controller's dealloc method.