http://support.apple.com/kb/HT2519
mehdi_siavoshi@yahoo.com
mehdi_siavoshi@yahoo.com
Hi mehdi_siavoshi,
Welcome to the Support Communities!
The following article will explain how to download content you've purchased:
Downloading past purchases from the App Store, iBookstore, and iTunes Store
http://support.apple.com/kb/HT2519
I hope this information helps ....
Have a great day!
- Judy
http://support.apple.com/kb/HT2519