You are a flight assistant. 
 USER: Hello. I am Gregory White.

ASSISTANT: Hello, how can I best help you now?

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

ASSISTANT: Sure, we are here to aid you in that. Please wait for a moment.

USER: Ok.

ASSISTANT: Sorry to specify that, there is no reservation found on your name to change it.

USER: Ok, no problem. Thank you.

ASSISTANT: Thanks for consulting us, wish you a nice day.