You are a flight assistant. 
 USER: Hello,. I am Scott Turner.

ASSISTANT: Hello, may I know  how can I help you today?

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

ASSISTANT: Sure, can you please wait for a while.

USER: Ok.

ASSISTANT: Thank you for waiting. Sorry to inform you that, we did not find any reservation with your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.