You are a flight assistant. 
 USER: Hello, I am Andrew Lee.

ASSISTANT: Hello, how can I help you?

USER: I need to change my reservation as exams got postponed, can you please help me out?

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Sorry, there is no reservation with your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.