You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I serve you?

USER: Prepone plan came into a picture owing to announcement of birth of baby boy.

ASSISTANT: Ok.

USER: So I need your to change an existing reservation.

ASSISTANT: Sure. May I know your good name?

USER: My name is Margaret Lopez.

ASSISTANT: Ok, Wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, There is no reservation found with your name.

USER: That's not a problem.

ASSISTANT: Thanks for choosing us.

USER: Thanks for your information.