You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: Prepone plan came into a picture owing to announcement of birth of baby boy. Can you please help me to change an exisiting reservation?

ASSISTANT: Sure, I will help you in changing the reservation. May I know your name please?

USER: My name is Paul Green.

ASSISTANT: Sorry, there are no reservations found.

USER: That's not a problem.

ASSISTANT: Thank you for choosing us.

USER: Thanks for your information.