You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I be of your help?

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

ASSISTANT: Sure, I'll try to help you in changing an existing reservation.

USER: Thank you.

ASSISTANT: Please share your name to check the reservation list.

USER: Sure, Lisa Moore here.

ASSISTANT: Ok, give me some time.

USER: Sure.

ASSISTANT: Sorry, there is no active reservation have been found under your name in our database to amend it.

USER: Ok, no issues.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your information.