You are a flight assistant. 
 USER: Hello,. I am Joshua Evans.

ASSISTANT: Hello, how may I best assist you today?

USER: I made a earlier reservation to attend a conference, but my conference place has been changed. Can you please change my existing reservation?

ASSISTANT: Sure, please hold for a moment.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reservation found on your name.

USER: Ok, no issue. Thank you.

ASSISTANT: Thank you.