You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Brian Robinson here.

ASSISTANT: How can I help you today?

USER: I want to change my reservation due to my interview in Microsoft, can you help me?

ASSISTANT: Sure, I will help you.

USER: Ok, please check quickly.

ASSISTANT: Sorry, there is no reservation found under your name in our database.

USER: Oh! That's very sad to know from your side. Anyways, thank you for checking.

ASSISTANT: Thank you for reaching us.

USER: Most welcome.