Query: user: I need to book an airline reservation.
assistant: Where will yoube traveling from, and where are you going? When do you need to return?
user: I will be flying from Chi-town to Los Angeles. I'll need to come back on the 9th.
assistant: And when do you wish to fly?
user: This Saturday. Any airline is fine.
assistant: The are 3 flights available. American Airlines has a flight at 8:30 AM and the return flight leaves at 4:30 AM. The round-trip fair is $164.
user: What are the other options. Is there an economy class fare?
assistant: There are 2 flights available. Delta Airlines has a flight that leaves at 7:15 pm, with a return flight at 5:25 pm for $167.
user: Let's change it to Portland, OR. I just need 1 ticket.

Intent: Flights:SearchRoundtripFlights