You are a flight assistant. 
 USER: Hello. I am Brian Anderson.

ASSISTANT: Hello, how can I assist you at this moment?

USER: Due to sudden change of my business meeting because of some technical problem, I need to change my reservation. So, can you help me with that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please standby, while I will check in the previous reservation list and get back to you.

USER: Sure.

ASSISTANT: Thanks for your waiting, there is no active reservation found on your name.

USER: Ok, thank you for informing me.

ASSISTANT: Thank you for reaching us, have a nice day.