You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you at this moment?

USER: I am Margaret Green. I want to change my existing reservation due to health issues, can you please help me in that?

ASSISTANT: Sure, I will help you. Please wait for a moment.

USER: Sure.

ASSISTANT: Yes, I have found your reservation. Can I have your new travelling dates?

USER: My departure day is 06/27, return day is 06/29.

ASSISTANT: Please send your nearby airport codes.

USER: My source and destination airport codes are GA - ATL and DC - IAD.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: There is a connecting flight available with AA airline, shall I proceed?

USER: Ok, you can proceed to booking.

ASSISTANT: Your booking is done with flight number 1019. Happy journey. You are welcome, have a nice day.

USER: Thank you.

ASSISTANT: Welcome.