You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: Please change my existing reservation owing to an emergency.

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: May I know your good name to track the details?

USER: My name is Margaret Hall.

ASSISTANT: Thanks for your time, there is no active reservation found on your name in our database.

USER: Thanks.

ASSISTANT: Thank you.