You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, what kind of assistance are you looking for?

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

ASSISTANT: Sure. May I know your name to check reservation?

USER: My name is Samuel Walker.

ASSISTANT: Please, wait for a while.

USER: Ok.

ASSISTANT: Thank you for your time. There is no active reservation found on your name.

USER: Thanks.

ASSISTANT: Thank you for approaching us.