You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: Can you change my reservation to new travel dates?

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

USER: Ok, I am Joseph Garcia.

ASSISTANT: Wait a moment please.

USER: Ok, take your time.

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

USER: That's ok, thank you.

ASSISTANT: Thank you for choosing us.