You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I want to change my existing reservation due to postpone of my board meeting so, can you please help me in changing my reservation?

ASSISTANT: Sure, please wait for a moment. May I know your name please?

USER: My name is Jacob Martin.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no flight reservation on your name to change it.

USER: No problem, thank you for the information.

ASSISTANT: Thank you.