You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Thomas Mitchell. I want to change my existing reservation due to postpone of my dance event. Could you please help me?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Sorry currently there is no reservation on your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you.