You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: My name is Betty Turner. I would like to change an existing reservation.

ASSISTANT: Ok, I can help you with that. Please be on hold.

USER: Sure, take your time.

ASSISTANT: Betty Turner, there is  no active reservation found active under your name to do modifications in that.

USER: No problem, thank you for the time.

ASSISTANT: Thank you for choosing us, have a great day.