You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. How can I serve you?

USER: I am Elizabeth Harris. Please book a ticket from Detroit, MI-DTW to Houston, TX-IAH, for science festival.

ASSISTANT: Sure, I will help you. Can I know your travelling dates?

USER: My departure date is 09/20 and will return by 09/22.

ASSISTANT: Do you need any connecting flight?

USER: Yes, please provide connecting flight.

ASSISTANT: We found a Spirit airline, flight number:1018 and the price is 200. Can I reserve it?

USER: Please reserve flight ticket.

ASSISTANT: Your flight ticket has been confirmed.

USER: Thanks for ticket confirmation.

ASSISTANT: Thank you for choosing us.