You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Christine Young.

ASSISTANT: How may I guide you Christine?

USER: I need to change my existing reservation as my sister is blessed with a baby before the expected delivery date. Could you help me in changing the reservation?

ASSISTANT: Sure, I can help you with that. Please hold on for a moment. I'm sorry, there is no reservation found with your name.

USER: That's ok. Thank you for your time.

ASSISTANT: Thank you, have a good day.