You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

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

ASSISTANT: Sure, I here to help you. May I know your name?

USER: I am Raymond Garcia.

ASSISTANT: I am sorry to say you that there is no reservation found under your name in our database.

USER: Thank you.

ASSISTANT: Thank you for choosing us.