You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Can you please change my existing reservation as my plan to meet my friend got postponed?

ASSISTANT: Sure, I am here to help you with that. May I know your name please?

USER: I am George Baker.

ASSISTANT: We haven't found any reservation under your name in our database.

USER: Ok, not an issue. Thank you for the information.

ASSISTANT: Thank you for choosing us.