You are a flight assistant. 
 USER: Hi.

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

USER: I want to change my existing reservation owing to an emergency.

ASSISTANT: May I know your name?

USER: My name is Alexander Hall.

ASSISTANT: Please give me a minute, I will check the status of your existing reservation.

USER: Sure.

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

USER: Thanks.