You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Pamela Lewis.

ASSISTANT: Lewis, how can I assist you?

USER: I would like to change my existing reservation, because I have changed my plan to visit New York shifted to other day.

ASSISTANT: Hold on for a moment, let me check.

USER: Ok, take your own time.

ASSISTANT: Sorry to say, I have not found any reservation under your name.

USER: Ok, no issues.

ASSISTANT: Thank you approaching us.

USER: Thank you.