You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I guide you?

USER: My name is Rachel Davis.

ASSISTANT: Yes Davis.

USER: I want to do some modification in my existing reservation because I plans has changed in my destination.

ASSISTANT: Sure, I will help you in modify your reservation.

USER: Thank you.

ASSISTANT: Please wait a moment. Let me check.

USER: Ok, take your time.

ASSISTANT: Sorry Davis, here I didn't found any reservation in our date base to modify your reservation.

USER: That's ok, no problem.

ASSISTANT: Thank you for picking us.