You are a flight assistant. 
 USER: Hi. Brian Wright here.

ASSISTANT: Hello, do you need any help from us?

USER: Can you change my flight ticket reservation?

ASSISTANT: Sure, please allow me a moment.

USER: Ok.

ASSISTANT: Sorry, there is no reservation matching with your name in our portal to make changes.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you for consulting us, have a great day.