You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may guide you?

USER: I am Raymond Scott. I am planning to change an existing reservation, due to some urgent work. Can you please change my reservation?

ASSISTANT: Sure Raymond, please give me a moment to check our database.

USER: Sure, take your own time.

ASSISTANT: Sorry Raymond, there is no reservation available as per our records. Thank you for reaching us.

USER: That's fine. Thank you for your help.