You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you at this moment?

USER: I am Gary Hill. Can you help me in changing my recent reservation, as my exam is postponed?

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

USER: Ok, I will be waiting.

ASSISTANT: Thank you for waiting. Sorry, there is no booking showing on your name.

USER: That's ok, thank you.

ASSISTANT: You are welcome. Thank you for reaching us, have a nice day.