You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Kevin Williams here.

ASSISTANT: How can I help you for today?

USER: I want to change my reservation today due to my office meeting, can you please help me?

ASSISTANT: Yes, I can help you.

USER: Ok, please check with my previous booking status and let me know the available information.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: Oh! That's very sad to know, thank you for checking anyways.

ASSISTANT: Thank you for consulting our agency.

USER: You are most welcome.