You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you?

USER: My name is Benjamin Smith. I need to change my existing reservation. Can you please help me with that?

ASSISTANT: Yes Benjamin. Hold on for a moment.

USER: Sure.

ASSISTANT: I'm sorry Benjamin, there are no reservations on your name.

USER: OK, thank you for the information. Have a great day.

ASSISTANT: Thank you.