You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: Can you please help me to change my recent reservation?

ASSISTANT: Sure. May I know your name please?

USER: Gregory Hill here.

ASSISTANT: Please wait.

USER: Sure, take your time.

ASSISTANT: Thanks for your time. Sorry to say that I could not find your flight reservation to change it.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you.