You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

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

ASSISTANT: Sure, we are here to help you. Can I have your name to proceed further?

USER: I am Daniel King.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Thank you for your valuable time, unfortunately no reservation found with provided name.

USER: Thanks.

ASSISTANT: Than you for approaching us.