You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, do you need any help from us?

USER: I am Amanda Mitchell, can you help me for changing my existing reservation?

ASSISTANT: Sure, I will help you out.

USER: Thank you.

ASSISTANT: Sorry Amanda, there is no reservation with your name to change further.

USER: Oh! It's ok, no problem thank you for your services.

ASSISTANT: My pleasure, have a nice day.