You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I would like to book a flight ticket from DEN, can you please assist me in making a plane reservation to DCA?

ASSISTANT: Can I know your travelling dates?

USER: My travelling dates are July 21st and July 23rd.

ASSISTANT: Is there any airline preference?

USER: No.

ASSISTANT: Do you have any preference?

USER: I will prefer to travel in a single connection.

ASSISTANT: Let me know your name.

USER: George Lee.

ASSISTANT: Direct flight is found with American airlines for price 100.

USER: Please reserve it.

ASSISTANT: Ticket is booked having flight number 1023.

USER: Thank you.

ASSISTANT: Thank you.