You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you?

USER: Could you please help me in booking a flight ticket from BOS to DEN?

ASSISTANT: Sure, can you share your trip dates?

USER: My trip dates are Aug 23 and Aug 25.

ASSISTANT: Do you have any preferences?

USER: No.

ASSISTANT: There is a direct flight with number 1004 in airline Frontier, the fare is 200 in economy class.

USER: Ok, proceed with the booking.

ASSISTANT: May I know your name?

USER: My name is Joseph White.

ASSISTANT: Your ticket is reserved, the depart time is 4:00 hours and return time is 12:00 hours.

USER: Thank you.

ASSISTANT: Thank you for reaching us.