Loading second view from first view not working -iphone

Question

I have an appdelegate(.h,.m) and two view controllers - loginviewcontroller, searchviewcontroller

On loginviewcontroller I have userid and password fields and login button. once login is verified searchviewcontroller view will be shown.

I have loginsuccess function defined in appdelegate and it is being called from loginviewcontroller.

AppDelegate

• (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

  loginviewcontroller *aViewController = [[loginviewcontroller alloc] initWithNibName:@"loginviewcontroller" bundle:[NSBundle mainBundle]]; self.loginviewcontroller=aViewController; [aViewController release];

  UIView *controllersView = [loginviewcontroller view]; [window addSubview:controllersView]; [window makeKeyAndVisible];

  return YES; }

• (void)loginSuccess {

  [[loginviewcontroller view] removeFromSuperview];

  SearchFormViewController *sformcontroller = [[SearchFormViewController alloc] initWithNibName:@"SearchFormViewController" bundle:[NSBundle mainBundle]]; self.searchformcontroller = sformcontroller; [sformcontroller release]; // UIView *searchfcontrol = [searchformcontroller view];

  [window addSubview:[searchformcontroller view]];

}

loginviewcontroller.h

@interface loginviewcontroller : UIViewController {

loginappDelegate *appDelegate;

} @property (nonatomic, retain) IBOutlet DiamondbyHKAppDelegate *appDelegate;

loginviewcontroller.m appDelegate = [[UIApplication sharedApplication] delegate];

[appDelegate loginSuccess];

But it is not loading the second view(searchviewcontroller). instead the app crashes and comes out. can someone please point out the mistake?