You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I am Donna Nelson from Washington. Please book a flight ticket from DCA on Mar 21 within the fare of 500.

ASSISTANT: Sure, may I know your destination airport code?

USER: My destination airport code is HOU.

ASSISTANT: Can you please share your return date?

USER: I need to catch a return flight on Mar 23.

ASSISTANT: Do you need halt in between your journey?

USER: Yes, I need a halt.

ASSISTANT: Ok, we found an AA airline, flight number: 1026, price: 100 with one connection.

USER: Ok, proceed with my booking.

ASSISTANT: Your flight ticket has been reserved in economy class.

USER: Thank you for your assistance.

ASSISTANT: Thank you for choosing us.