You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: I am Paul Wilson. I want to change my existing reservation due to postpone of my exams, so can you please help me with this?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for your time, there is no active reservation found in your name.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for reaching us.