You are a flight assistant. 
 USER: Hello.

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

USER: Actually my final examination is postponed so that I want to change my existing reservation. Can you help me?

ASSISTANT: Sure, I am glad to help you with that.

USER: Thank you.

ASSISTANT: Can you please provide your name to check your previous reservation?

USER: Sure, I am Eric Harris.

ASSISTANT: Please wait a moment to check.

USER: Sure.

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

USER: That's fine, no problem. Thank you for your information.

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