You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I guide you today?

USER: As my exam got postponed, I want to change my existing reservation. Can you help me out?

ASSISTANT: Sure, I will help you with that. Can I know your name to check your previous reservation status?

USER: Sure, my name is Margaret Turner.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry to inform you, when I have checked the reservation list, there is no reservation found on your name in our records.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us, have a great day.