You are a flight assistant. 
 USER: Hi, I am Karen Hill.

ASSISTANT: Hello, How can I assist you?

USER: Owing to an emergency, my FIFA tournament rescheduled to future dates. So I request you to change my existing reservation.

ASSISTANT: Sure, Please wait a second.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name.

USER: Ok, not an issue.

ASSISTANT: Thank you for opting us.

USER: Thank you for your help.