You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Can you please change my reservation?

ASSISTANT: Sure, I can do that for you. May I know your name?

USER: Robert Baker here.

ASSISTANT: Thank you. Please wait for a while, let me check your reservation status in our database.

USER: Sure, take your time.

ASSISTANT: Sorry, no reservation found under your name in our database.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome and thank you for choosing us.