Why does Samsung I8000 send a text message showing that the specified address is invalid?

You can enter someone's name directly into the recipient, right? This I8000 can't be sent. Unlike many other mobile phone recipients, you can directly enter the Chinese name, as long as there is this person's name in the phone book. I8000 can't. You can only click the magnifying glass on the right to choose, or enter the mobile phone number.