You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you for today?

USER: I would like to change my existing reservation, please help me out.

ASSISTANT: May I know your name?

USER: I am Jack Walker.

ASSISTANT: Can you please provide your new airport codes?

USER: My airport codes are OAK and DCA.

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: I would like to start my journey on 06/28 and return on 06/30.

ASSISTANT: Here is a flight with ticket fare 200 in Spirit airlines with connection 1, would you like me to proceed with the booking?

USER: Please confirm my booking.

ASSISTANT: Your booking is confirmed with flight number 1012.

USER: Thank you for your response.

ASSISTANT: Thank you for contacting us, have a nice day.