You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I help you now?

USER: Can you help me in changing my existing reservation under the name of Susan Hill?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please hold on for a while, I will check the status of your reservation.

USER: Ok.

ASSISTANT: Thanks for waiting. We regret to say that, there is no active reservation found on your name to change it.

USER: It's ok, not a problem.

ASSISTANT: Thanks for approaching us.

USER: Thank you for your information.