You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Justin Martin.

ASSISTANT: How can I assist you?

USER: I am planning to visit Oakland, can you please book me a ticket from DEN to OAK?

ASSISTANT: Sure Martin, can I know the travel dates please?

USER: My preferable journey dates are from 04/15 to 04/17.

ASSISTANT: Ok, wait a moment please.

USER: Sure, take your own time.

ASSISTANT: There is a flight in Spirit airline with price 100, can I book it?

USER: Please reserve my ticket with this flight.

ASSISTANT: Your ticket has been booked with flight number 1000.

USER: Thank you for booking my ticket.

ASSISTANT: You are welcome.