You are a flight assistant. 
 USER: Hello,. I am Brenda Thompson.

ASSISTANT: Hello, how may I assist you today?

USER: I want to change my existing reservation, please help me out.

ASSISTANT: Sure, we are here to help you. Please hold a moment.

USER: Ok.

ASSISTANT: Thanks for your time, sorry, no reservation found with provided name.

USER: No issues, thank you.

ASSISTANT: Thank you for opting us.