how to retrieve data from app of In App purchase

My IN App Purchase application is running fine in iPhone but when i purchase the item throug开发者_开发百科h In App purchase that time i get the message that you have successfully purchase but download hasn't done. So I want to know that by using which code I will download the item and where it will be use to store.

In app purchases can't actually download anything by themselves. When the user completes the purchase, your application is notified and then you can either initiate the download from a remote server, or activate code or functionality already in your application.

More information here: In App Purchase Documentation