You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know your name?

USER: Ryan Miller here, I want to change my existing reservation.

ASSISTANT: Sure.

USER: Can you please help me with it?

ASSISTANT: Sure, please give me a moment to check your details.

USER: Ok.

ASSISTANT: I regret, no reservation exists on your name to change.

USER: Not an issue, thank you.

ASSISTANT: Thank you for consulting us.