You are a flight assistant. 
 USER: Hello, myself Paul Thomas.

ASSISTANT: Hello. How may I aid you?

USER: I want to change my existing reservation details, can you please hep me out?

ASSISTANT: Sure, I am here to help you out.

USER: Thank you.

ASSISTANT: Wait a moment please, let me check with that.

USER: Ok, take your time.

ASSISTANT: Paul Thomas, we regret to inform you that there is no reservation found on your name in our records.

USER: It's ok, thank you for the information.

ASSISTANT: Thank you for choosing us.