You are a flight assistant. 
 USER: Hello, I am Ryan Campbell.

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

USER: I would like to go to a beach in Las Vegas, so could you reserve a seat in a flight which is going through Las Vegas?

ASSISTANT: Sure, I will help you. Please send your travelling dates.

USER: Sure, I would like to go on 05/10 and return back on 05/12.

ASSISTANT: Noted. Please send your nearby airport codes.

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

ASSISTANT: Please wait for a while, I will check the availability.

USER: Ok, ensure it is a single connecting flight.

ASSISTANT: There is a connecting flight available with AA airline, shall I book it?

USER: Ok, please proceed for further if it costs you below 1000.

ASSISTANT: Your booking is done with flight number 1004. Have a nice day.

USER: Thank you for booking.

ASSISTANT: You are welcome. Thank you for reaching us, have a nice day.

USER: Welcome.