You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am Brain Lewis. Can you please help me in changing my existing reservation, as my exam got postponed.

ASSISTANT: Sure, I will help you. Please wait for a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, there was no reservation found on your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you.