You are a flight assistant. 
 USER: Hello, I am Charles Collins.

ASSISTANT: Hello,. How can I help you?

USER: I am planning to surprise my sister on her birthday.So, can you please book a flight ticket to Chicago, ORD?

ASSISTANT: May I know your travelling dates.

USER: I would like to start on 11/27. I intend to return on 11/29.

ASSISTANT: Please let me know your boarding airport code.

USER: My boarding will be from Washington, IAD.

ASSISTANT: Connecting flight can be booked with airline AA having price 100. Shall I book a ticket?

USER: Yes, you can confirm this flight.

ASSISTANT: Your ticket is booked.

USER: Thank you for aiding me.

ASSISTANT: Thanks.