You are a flight assistant. 
 USER: Hi. I am Helen Phillips.

ASSISTANT: Hello, how may I aid you?

USER: Can you help me in changing my reservation, as my exam is postponed.

ASSISTANT: Sure, I will help you with the change of flight reservation.

USER: Ok.

ASSISTANT: I have searched online but I could not find your flight reservation to cancel it.

USER: No issue, thank you.

ASSISTANT: Thank you.