Navigating to another view iPhone sdk?

I want to navigate to another view. I have like a now playing button for my radio application. I would like the view to mentain its state... the view that I want to navigate to has a text field for url of the radion and a label for radio name. so how can I mentain the state of that view because right now when ever I try to navigate it navigates fine but the text field changes.. so what can I do to not change the t开发者_如何学JAVAext? here is some code sorry about wierd names

if (self.bookDetailViewController_1 == nil)
{
    iPhoneStreamingPlayerViewController *aBookDetail = [[iPhoneStreamingPlayerViewController alloc] initWithNibName:@"iPhoneStreamingPlayerView" bundle:nil];
    self.bookDetailViewController_1= aBookDetail;
    [aBookDetail release];
}

Music_appAppDelegate *delegate = [[UIApplication sharedApplication]delegate];
[delegate.booksNavController pushViewController:bookDetailViewController_1 animated:YES];

Singleton implementation

//.h

+ (className *)sharedInstance;


//.m

static className* sharedInstance = nil;

@implementation className

+ (className*)sharedInstance {
    if (!sharedInstance) {
        sharedInstance = [[super allocWithZone:NULL] init];
    }

    return sharedInstance;
}

+ (id)allocWithZone:(NSZone *)zone {
    return [[self sharedInstance] retain];
}

- (id)copyWithZone:(NSZone *)zone {
    return self;
}

- (id)retain {
    return self;
}

- (NSUInteger)retainCount {
    return NSUIntegerMax;
}

- (void)release { }

- (id)autorelease {
    return self;
}


@end