You are a flight assistant. 
 USER: Hi.

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

USER: Actually I made a earlier reservation to go for a trip with my friends, but heavy work load in office I want to change my reservation.

ASSISTANT: I will help you with that. May I know your name?

USER: Christopher Harris is my name.

ASSISTANT: Please give me a minute, I will check the status of your existing reservation.

USER: Ok.

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

USER: That's ok, thank you.

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