You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you?

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

ASSISTANT: Sure, may I know your name for checking?

USER: My name is Dennis Davis.

ASSISTANT: Give me a minute.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found under your name.

USER: Thank you.

ASSISTANT: Thank you for reaching us.