If the iphone is upgraded to IOS5, will the address book and SMS be erased? If so, what should I do? Back up and restore with ITUNES?

Every time you connect your phone to itunes, itunes will automatically synchronize information for you. In fact, this is to back up the data in the mobile phone. After your mobile phone is upgraded to ios5 with itunes, the data in it will be erased. However, when itunes installs a brand-new ios5 firmware for your mobile phone, it will automatically restore the data previously backed up for your mobile phone to your mobile phone. Therefore, before and after the upgrade of your mobile phone, call records, contacts, information and so on will remain intact in your mobile phone.

hope this helps ...