You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Sandra White. I had planned to go on a vacation, but it was postponed due to some reasons. Can you change my recent reservation?

ASSISTANT: Please wait a while.

USER: Ok, take your time.

ASSISTANT: There is a reservation on your name, please share your desired travel dates.

USER: I want to travel in the flight on 05/01 and 05/03.

ASSISTANT: May I know your desired airport codes please?

USER: I want to travel from DCA to IAD.

ASSISTANT: There is a flight with connection limit 1 and fare 100, shall I proceed for booking?

USER: Proceed to booking.

ASSISTANT: Your ticket is booked, flight number 1007.

USER: Thank you for your help.

ASSISTANT: Thank you for opting us.