popToRootViewController when application enters background
===

In the `didFinishLaunchingWithOptions` of my application , the code is 

       _homeViewController = [[HomeViewController alloc]init];
        UINavigationController*  _navigationController = [[UINavigationController alloc] initWithRootViewController:_homeViewController];
        [self.window setRootViewController:_navigationController];
        [_navigationController setNavigationBarHidden:YES];
        [self.window makeKeyAndVisible];
and in the `HomeViewController` , I am having two buttons, If the button is pressed , I am presenting the ViewController. If button1 is pressed , the code is 

    if (_detailsViewController == nil)
                _detailsViewController = [[DetailsViewController alloc]init];
            
           [self.navigationController presentModalViewController:_detailsViewController animated:YES];

Now when I am in the detailsViewController and I pressing the iPhone Home button, in the same class I am using the `UIApplicationDidEnterBackgroundNotification` and calling a method to execute the following line  

    [self.navigationController popToRootViewControllerAnimated:YES];

So I thought when I open the application again, I can see the HomeViewController, but it doesn't work. Please help me !!

