You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Robert Gonzalez.

ASSISTANT: How can I assist you?

USER: I want o join the city walking tour with my friend in Washington. Can you book me a ticket from DCA to IAD?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Could you please let me know your preferable journey dates?

USER: I would start on Sept 8th and return Sept 10th.

ASSISTANT: Do you have any airline preference?

USER: Yes, I need a normal cost airline.

ASSISTANT: In which class would you like me to book your flight ticket?

USER: I would prefer a business class ticket.

ASSISTANT: Ok, wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting, there is a ticket available in business class having single connection. Shall I confirm your ticket in UA airline?

USER: Fine, please go ahead.

ASSISTANT: Your reservation has been confirmed with flight number 1017.

USER: Thanks for your service.

ASSISTANT: Thank you for opting us.