You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I just want to change an existing reservation due to my seminar got postponed.

ASSISTANT: Sure, may I know your name?

USER: Monk Jones is my name.

ASSISTANT: Please wait for a while, I will check and get back to you.

USER: Ok.

ASSISTANT: Sorry to tell that there is no reservation on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for approaching us.