You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: Owing to an emergency I want to change my existing reservation, can you please help me with this?

ASSISTANT: May I know your name?

USER: My name is Emma Clark.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there are no reservation found on your name.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for choosing us.