You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

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

ASSISTANT: Sure, I am here to help you for this. Let me check your reservation status in our database.

USER: Ok.

ASSISTANT: For changing the reservation. May I know your name please?

USER: I am Paul Wright.

ASSISTANT: Please wait for a while. Sorry to inform, no reservation is found with your criteria.

USER: Thank you.

ASSISTANT: Thank you very much for reaching us.