You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Richard Wilson.

ASSISTANT: How can I serve you the best today?

USER: I want to change my existing reservation. Could you help me with that?

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: There is no reservation found with your given name.

USER: That's ok, no problem. Thank you for helping me.

ASSISTANT: Thank you for choosing us.