You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jacob Young.

ASSISTANT: How may I assist you?

USER: I need to change my existing reservation as my exams got postponed, Can you please help me with that?

ASSISTANT: Sure, I am here to help you out.

USER: Thank you.

ASSISTANT: Jacob Young, we regret to inform you that there is no reservation found on your name in our records.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for approaching us.