You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you for today?

USER: I am Andrew Carter, I want to change my reservation which I have done last week.

ASSISTANT: Yes, I will help you with that. Sorry Andrew, there is no active reservation under your name.

USER: Not a problem, anyway thank you for the information.

ASSISTANT: My pleasure, thank you for reaching out here.