You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I need to change my existing reservation as my sister blessed with a baby before the expected delivery date.

ASSISTANT: Sure, May I know your name?

USER: My name is Matthew Lopez.

ASSISTANT: Yes Lopez, no reservation found for you.

USER: That's fine, thank you for your help.

ASSISTANT: You are welcome, have a nice day.

USER: Thank you.