You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER:  I am Christopher Smith want to attend food festival at Houston,TX-HOU with my friends. Can you book a ticket from DC-IAD?

ASSISTANT: Sure, I can help you out. When would you like to travel?

USER: My travel dates are. My travel dates are 12/20 and 12/22.

ASSISTANT: Do you need connecting flight?

USER:  I need a connecting flight.

ASSISTANT: We found a UA airline, flight number:1027 and the price is 200.

USER:  Ok, you can proceed with the booking.

ASSISTANT: Your flight ticket has been reserved.

USER:  Thank you for booking.

ASSISTANT: Thank you for consulting us.