You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you for today?

USER: I want to change my existing reservation. Can you please help me with this?

ASSISTANT: I am here to help you about that. Can you please provide your name to check the reservation status?

USER: Scott Wilson here.

ASSISTANT: Please wait for sometime to check in our booking list.

USER: Sure.

ASSISTANT: Sorry for the trouble which is caused to you, I have not found any reservation on your name in our database.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: You are welcome, thank you for reaching us.