You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I'm Andrew Brown.

ASSISTANT: How can I help you Andrew Brown?

USER: I want to change my reservation because, the friend I was going to visit previously is out of town.

ASSISTANT: Ok, wait a moment please.

USER: Ok, sure.

ASSISTANT: Sorry to say, there is no reservation found with your name to change.

USER: No problem with it.

ASSISTANT: Thank you and have a great day.

USER: Thank you for your service.