You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Myself Timothy Johnson. I just want to change my existing reservation, because my seminar was postponed.

ASSISTANT: Sure, give me a moment.

USER: Ok.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: Ok, that's fine. Thank you for your services.

ASSISTANT: You are welcome.