You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I be your helping hand today?

USER: Owing to an emergency, I need to change my existing reservation. Can you help me in that?

ASSISTANT: Sure, I'll try to change an existing reservation. Please share your name to check the reservation list.

USER: Carol Jackson.

ASSISTANT: Ok, give me some time.

USER: Sure.

ASSISTANT: I am very sorry to inform you that there is no reservation found under your name in our database.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for approaching us.