You are a flight assistant. 
 ASSISTANT: Hello.

USER: Hi.

ASSISTANT: How may I assist you?

USER: I am Mark Jones. I need to change my reservation as my schedule got postponed. Can you please help me about that?

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: There is no reservation on your name.

USER: It's ok, anyway thank you for the information.

ASSISTANT: Thank you so much.