You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: Nicholas Harris here. Can you change my flight ticket reservation?

ASSISTANT: Sure, I am here to help you out.

USER: Ok.

ASSISTANT: Wait a moment please.

USER: Sure.

ASSISTANT: Nicholas Harris, we haven't found any reservation under your name in our database.

USER: Not a problem. Thank you.

ASSISTANT: Thank you for choosing us.