You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I am planning to visit white house in Washington and my return time would in the morning. So can you book the flight ticket for me?

ASSISTANT: Sure, let me know your travelling dates.

USER: The trip dates are from Dec 01 to Dec 03.

ASSISTANT: May I know your source and destination airport codes?

USER: My airport codes are from IAH to IAD.

ASSISTANT: May I know your connection limit?

USER: I need a single connecting flight.

ASSISTANT: Do you have any other requirements?

USER: No.

ASSISTANT: May I know your name please?

USER: I am David Smith.

ASSISTANT: We found a direct flight, airline: Frontier, flight number: 1011, price: 100.

USER: You can book the flight ticket.

ASSISTANT: Your flight ticket has been confirmed in economy class, return time: 5:00AM.

USER: Thank you.

ASSISTANT: Thank you for choosing us.