...
1. Go to dialing mode
2. Click on the Keypad tab
3. Type ##5005*86#
4. Tap Call
Calling the VoiceMail number
1. Go to dialing mode
2. Tap the VoiceMail button
For more instructions on synchronizing:
Download a manual from http://support.apple.com/manuals/iphone
Backup Back up your phone to iCloud
Apple instructions on iCloud backups at http://support.apple.com/kb/PH12519?viewlocale=en_US
Apple iPhone 4