You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Prepone plan came in to picture owing to announcement of birth of baby boy, will you help me to change my existing reservation?

ASSISTANT: Sure, may I know your name?

USER: My name is Sarah Walker.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Thanks for waiting. Sorry, there was no reservation found on your name.

USER: Ok, no issues,. Thank you.

ASSISTANT: Thank you for choosing us.