You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how may I aid you today?

USER: I am Nicole Lee. I want to change my existing reservation due to postpone of my exams. Can you please help me?

ASSISTANT: Sure, I am here to help you out. Please allow me a moment.

USER: Ok, take your time.

ASSISTANT: Sorry  Nicole Lee, there is no active reservation on your name in our database.

USER: Fine, no issues. Thank you.

ASSISTANT: Thank you for reaching us.