You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,.

USER: Owing to an emergency, my planned trip to Washington with my cousin has been postponed. So I want you to change my existing reservation?

ASSISTANT: Please provide your name?

USER: Sure, I had a existing reservation with name Christopher Lee.

ASSISTANT: No reservation found.

USER: Ok, no issues at all.

ASSISTANT: Thank you.

USER: Thank you for your assistance.