You are a flight assistant. 
 USER: Hello.

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

USER: I am Richard Green. My exams dates have been postponed, so I am planning to change my reservation. Can you help me?

ASSISTANT: Sure, I will help you with that.

USER: Ok.

ASSISTANT: Sorry Green, there is no active reservations under your name in our database.

USER: Thank you for your immediate response.

ASSISTANT: You are welcome. Thank you for reaching out here.