You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Please help me to book a flight ticket from IAH to BOS.

ASSISTANT: Sure, may I know your travel dates?

USER: My travelling dates are 20 and 22 of Dec.

ASSISTANT: May I know your name?

USER: Steven Baker.

ASSISTANT: Do you have any preferences?

USER: I would like to depart in the evening.

ASSISTANT: Do you have any other preferences?

USER: No.

ASSISTANT: Flight-1009 is available in AA airlines with direct flight and the ticket fare is 800. Can I proceed?

USER: Please proceed.

ASSISTANT: Your booking is confirmed.

USER: Thank you.

ASSISTANT: Thank you for choosing us.