You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

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

ASSISTANT: May I know your name please?

USER: My name is Jack Clark.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name to change.

USER: Thank you.

ASSISTANT: Thank you for reaching us.