You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

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

ASSISTANT: Sure, I will help you. May I know your name please to check your reservation status?

USER: My name is Frank Hill.

ASSISTANT: Frank Hill, no reservation has been found on your name in our database.

USER: Thanks.

ASSISTANT: Thank you for choosing us.