You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

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

ASSISTANT: Sure, may I know your name?

USER: I am Charles Young.

ASSISTANT: Please wait a second.

USER: Ok.

ASSISTANT: Sorry, no reservation found on your name.

USER: Thank you.

ASSISTANT: Thank you for availing us.