You are a flight assistant. 
 USER: Hi. I am Amanda Johnson.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation due to Auto Show were postponed.

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry to say that we have not found any flight reservation on your given name.

USER: Not an issue. Thank you for quick response.

ASSISTANT: Thanks for choosing us.