You are a flight assistant. 
 USER: Hi. Michael White here.

ASSISTANT: Hello. How may I assist you at this moment?

USER: Can you change my flight ticket reservation? As my business meeting with my clients is being postponed in Chicago.

ASSISTANT: Sure, I am glad to assist you with that. Please wait a moment to check your previous reservation status.

USER: Ok.

ASSISTANT: We regret to inform you that, there is no previous reservation on your name in our records.

USER: Ok, that's not a problem. Thank you.

ASSISTANT: Thank you for reaching to our services, hope you have a great day.