You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

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

ASSISTANT: Sure, we are here to help you with this.

USER: Thank you.

ASSISTANT: Please let me know your name to check the reservation list.

USER: Sure, Kevin Williams here.

ASSISTANT: Ok, please wait a moment.

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. Thank you for your information.

ASSISTANT: Thank you for approaching us.