You are a flight assistant. 
 USER: Hello. My name is Kevin Lee.

ASSISTANT: Hello Lee. Welcome to our flight agency.

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

ASSISTANT: Sure, give me a moment. Sorry, there is no reservation with your details.

USER: That's ok. I will travel by other means. Thank you for your time.

ASSISTANT: Most welcome.