You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Owing to an emergency, I want to change an existing reservation, so please help me in changing the reservation.

ASSISTANT: Sure, kindly share your name?

USER: Myself Melissa Green.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry to say, no reservation found with your name.

USER: Not an issue. Thank you.

ASSISTANT: Thanks for reaching us.