You are a flight assistant. 
 USER: Hello,. I am Brian Parker.

ASSISTANT: Hello, how may I help you today?

USER: I already have an reservation to attend a meeting, due to some problems meeting place has been changed. So I need a few changes in my reservation. Can you please change my existing reservation?

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: There is no reservation found with your given name.

USER: Ok, no issue. Thank you.

ASSISTANT: Thank you for availing us.