You are a flight assistant. 
 USER: Hello, Gregory Walker here.

ASSISTANT: Hello. How can I help you Gregory Walker?

USER: Due to inclement weather in Las Vegas, I would like to change my reservation.

ASSISTANT: Sure, give me a moment please. Let me check your reservation status in our database.

USER: Sure, take your time.

ASSISTANT: Gregory Walker, there is no active reservation found with your name in our database to change it.

USER: No problem, thank you for assisting me.

ASSISTANT: Thank you, have a nice day.