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If the same contact appears more than once in your phone's address book, you can merge identical contacts so that they will appear only once.
1. Open the address book
Press the contacts icon.
2. Merge identical contacts
Press the menu icon.
Press Organise contacts.
Press Merge duplicate contacts.
Press the field next to the required contact.
3. Return to the home screen
Press the Home key to return to the home screen.