How to do in-app purchase in ios5?

I have used the following code for in-app purchase.

- (void)viewDidLoad { if ([SKPaymentQueue canMakePayments]) {     NSLog(@"Can Buy Product");     SKProductsRequest *productRequest=[[SKProductsRequest alloc]initWithProductIdentifiers:[NSSet setWithObject:@"com.mycompany.myproduct.productpack"]];     productRequest.delegate=self;     [productRequest start]; } else {     NSLog(@"Product Can't be purchased"); } } -(IBAction)purchasePack1 { SKPayment *payment=[SKPayment paymentWithProductIdentifier:@"com.mycompany.myproduct.productpack"]; [[SKPaymentQueue defaultQueue] addTransactionObserver:self]; [[SKPaymentQueue defaultQueue] addPayment:payment]; } -(void)productsRequest:(SKProductsRequest *)request didReceiveResponse:(SKProductsResponse *)response { validProduct=nil; int count=[response.products count]; if (count>0) {     NSLog(@"Product Avail");     validProduct=[response.products objectAtIndex:0]; } else {     NSLog(@"No Product avail");     [purchaseBtn setHidden:TRUE]; } } -(void)paymentQueue:(SKPaymentQueue *)queue updatedTransactions:(NSArray *)transactions { for (SKPaymentTransaction *transaction in transactions) {     switch (transaction.transactionState) {         case SKPaymentTransactionStatePurchasing:             NSLog(@"Purchasing");               [activityIndicatorObj setHidden:FALSE];             [activityIndicatorObj startAnimating];             break;         case SKPaymentTransactionStatePurchased:             UIAlertView *alt=[[UIAlertView alloc]initWithTitle:@"Congrats" message:@"Thanks For Purchasing " delegate:self cancelButtonTitle:@"Dismiss" otherButtonTitles:nil];             [alt show];             [alt release];             NSLog(@"Purchased");             [activityIndicatorObj stopAnimating];             [activityIndicatorObj setHidden:TRUE];             [[SKPaymentQueue defaultQueue] finishTransaction:transaction];             break;             case SKPaymentTransactionStateFailed:             if (transaction.error.code!=SKErrorPaymentCancelled) {                 NSLog(@"Cancelled");             }             [[SKPaymentQueue defaultQueue] finishTransaction:transaction];             UIAlertView *alt1=[[UIAlertView alloc]initWithTitle:@"Sorry" message:@"Some Error Encountered!" delegate:self cancelButtonTitle:@"Dismiss" otherButtonTitles:nil];                 [alt1 show];                 [alt1 release];             NSLog(@"Failed");             [activityIndicatorObj stopAnimating];             [activityIndicatorObj setHidden:TRUE];             break;             case SKPaymentTransactionStateRestored:             NSLog(@"Restored");             [activityIndicatorObj stopAnimating];             [activityIndicatorObj setHidden:TRUE];             [[SKPaymentQueue defaultQueue] finishTransaction:transaction];             break;         default:             break;     } } }