hey, I'm currently using the iPhone SDK and I'm having trouble passing an NSString through 3 views

I am able to pass an NSString between 2 view controllers but I am unable to pass it through another one. My code is as follows...

    `- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)index`Path {

 NSString *string1 = nil;

 NSDictionary *dictionary = [listOfItems objectAtIndex:indexPath.section];
 NSArray *array = [dictionary objectForKey:@"items"];
 string1 = [array objectAtIndex:indexPath.row];


 //Initialize the detail view controller and display it.
 ViewController2 *vc2 = [[ViewController2 alloc] initWithNibName:@"ViewController2" bundle:[NSBundle mainBundle]];
 vc2.string1 = string1;
 [self.navigationController pushViewController:vc2 animated:YES];
 [vc2 release];
 vc2 = nil;
}

in the "ViewController 2" implementations I am able use "string1" in the title bar by doing the following....

    - (void)viewDidLoad {
    [super viewDidLoad];
    self.navigationItem.title = string1;
 UIBarButtonItem *addButton = [[[UIBarButtonItem alloc]
           initWithImage:[UIImage imageNamed:@"icon_time.png"] 
           style:UIBarButtonItemStylePlain
           //style:UIBarButtonItemStyleBordered
           target:self
           action:@selector(goToThirdView)] autorelease];
 self.navigationItem.rightBarButtonItem = addButton;

    }

but I also have a NavBar Button on the right side that I would like to push a new view

- (void)goToThirdView 
    { 
     ViewController3 *vc3 = [[ViewController3 alloc] initWithNibName:@"ViewController3" bundle:[NSBundle mainBundle]];

     [self.navigationController pushViewController:NESW animated:YES];
     vc3.string1 = string1 ;
     [vc3 release];
     vc3 = nil;
}

How do I pass on that same string to the third view? (or fourth)