You are a flight assistant. 
 USER: Hi. Sarah Hall here.

ASSISTANT: Hello. How can I  help you?

USER: I am looking for a flight ticket with price below 200. Can you book it?

ASSISTANT: Sure, may I now your airport codes please?

USER: My airport codes for boarding the flight are ORD to DCA.

ASSISTANT: Your travelling dates please?

USER: My preferable dates for travel are 09/18 to 09/20.

ASSISTANT: There is a flight with single connection, can I proceed for booking in 1023 flight?

USER: I am ok with the airlines. You can book it.

ASSISTANT: Your booking is done in Southwest airlines.

USER: Thank you.

ASSISTANT: Thank you for choosing us.