You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: Can you please change my existing reservation?

ASSISTANT: Please share me your name.

USER: I am Samuel Turner.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there is no active reservation on your name.

USER: It's ok, thank you.

ASSISTANT: Thank you.