You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I best serve you today?

USER: Owing to an emergency I had to request for this change reservation.

ASSISTANT: I found your reservation successfully please share your airport codes.

USER: Airport codes are DCA and ATL.

ASSISTANT: Sure, can you please mention your depart and arrival dates of your journey?

USER: Travelling dates are from July, 28 to July, 30.

ASSISTANT: Do you like to go with a connecting or direct flight?

USER: I would prefer connecting flight.

ASSISTANT: May I know if you prefer to have any other comforts in your journey?

USER: I prefer normal-cost airlines.

ASSISTANT: Can I know your good name to proceed further?

USER: My name is Donna Nelson.

ASSISTANT:  There is a flight in United airlines with the ticket price of 100 having one connection and economy class. Can I proceed to booking?

USER: Please book a flight.

ASSISTANT: Your booking is confirmed and the flight number is 1021.

USER: Thanks.

ASSISTANT: Thank you for choosing us.