You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I assist you today?

USER: Please change my existing reservation owing to an emergency.

ASSISTANT: Sure, I am here to help you with this. May I know your name please?

USER: I am Elizabeth Lee.

ASSISTANT: Please wait for a mean while to check for the availability.

USER: Sure.

ASSISTANT: Sorry Lee, there is no reservation found as per your name to change your reservation.

USER: Thanks.

ASSISTANT: You are welcome always.