How to Verifying Store Receipts for Mac

Question

I don't know how to verifying store receipts for mac.
When and Where to check verifying store receipts?
This is my code.  Is it correct ?  and Where to check receipts?  and how to verifying store receipts? 
Please help me.
1 .
if (   [SKPaymentQueue canMakePayments] )
2. SKProductsRequest *request =  [[SKProductsRequest alloc] initWithProductIdentifiers:[NSSet setWithObject:@"com.mac.point500"]];
   request.delegate=self;
   [request start];
3.
-(void)productsRequest:(SKProductsRequest *)request didReceiveResponse:(SKProductsResponse *)response{
   SKProduct *product = [response.products objectAtIndex:0];
   NSLog(@"Title : %@", product.localizedTitle);
   NSLog(@"Description : %@", product.localizedDescription);
   NSLog(@"Price : %@", product.price);
  [[SKPaymentQueue defaultQueue] addTransactionObserver:self];
   SKPayment *payment = [SKPayment paymentWithProduct:product];
   [[SKPaymentQueue defaultQueue] addPayment:payment];
4.
- (void)paymentQueue:(SKPaymentQueue *)queue updatedTransactions:(NSArray *)transactions{
          for(SKPaymentTransaction *transaction in transactions){
                    switch(transaction.transactionState)
            case SKPaymentTransactionStatePurchasing:
                       break;
            case SKPaymentTransactionStatePurchased:
                  [self purchasedTransaction:transaction];
                                             break;
            case SKPaymentTransactionStateFailed:
                  [self failedTransaction:transaction];
                                             break;
            case SKPaymentTransactionStateRestored:
                  [self restoreTransaction:transaction];
                                             break;
            default:
                                             break;
5.
-(void)purchasedTransaction:(SKPaymentTransaction *)transaction
     m_point +=  500 ; // purchase success.
     [[SKPaymentQueue defaultQueue] finishTransaction:transaction];
6.
- (void)paymentQueue:(SKPaymentQueue *)queue removedTransactions:(NSArray *)transactions

Answer 1

MacBook Pro
https://discussions.apple.com/community/notebooks/macbook_pro 
https://discussions.apple.com/community/mac_os?view=discussions
http://www.apple.com/support/macbookpro