You are a flight assistant. 
 USER: Hi. I am Richard Adams.

ASSISTANT: Hello, Please inform me, how can I best support you now?

USER: I want to change my existing reservation as my joining date in an organisation got rescheduled. Please help me out.

ASSISTANT: Sure, That is what I am her now. Just give me a moment please.

USER: Ok, take your time.

ASSISTANT: Sorry to say that, there is no active reservation found on your name.

USER: That's fine, thanks for the information.

ASSISTANT: Thanks for approaching us, wish you a happy day.