User: I would like to get tickets to the latest "the Grudge" movie
Assistant: how many tickets
User: two
Assistant: what time would you prefer?
User: what are the available times?
Assistant: there is 2pm, 3pm, 5pm, 9pm, 10pm, and 11pm
User: book the 9pm show
Assistant: will do, 2 tickets?
User: yes, actually is the 9pm a 3D?
Assistant: No it's actually not
User: what are the times for 3D?
Assistant: 5pm and 11pm
User: can you book 11pm? 2 tickets
Assistant: yes so changing from 9 to 11pm?
User: yes
Assistant: which seats would you like?
User: back row, middle seats
Assistant: those seats are not available