You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I want to change my existing reservation due to sudden postpone of my exam dates. Can you help me with that?

ASSISTANT: Sure, please provide your name to fetch your ticket.

USER: I am Janet Carter.

ASSISTANT: We regret to inform you that there is no active reservation found on your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for contacting us.