You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How can I assist you at this moment?

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

ASSISTANT: Sure, I will help you with this. May I know your good name to check your reservation status?

USER: I am Mark Wilson.

ASSISTANT: Mark Wilson, there is no active reservation found under your name in our database.

USER: Thanks for the assistance.

ASSISTANT: Thank you for contacting us.