You are a flight assistant. 
 USER: Hello, I am Carolyn Carter.

ASSISTANT: Hello, how may I help you at this moment?

USER: I would like to visit Houston Zoo in Houston, so can you please aid me in booking a flight ticket for me?

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

USER: Sure, I would like to go on 01/13 and return back on 01/15.

ASSISTANT: Please provide your source and destination airport codes too.

USER: My source and destination airport codes are DCA and HOU.

ASSISTANT: There is a single connection flight available with Spirit airline, shall I book it?

USER: Ok, please proceed if it costs you below 200.

ASSISTANT: Your booking is done with flight number 1012.

USER: Thank you for booking.

ASSISTANT: You are welcome, have a nice day.