You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I help you?

USER: As I need to fly Las Vegas please book a ticket.

ASSISTANT: Sure, we are here to help you. May I know when are you planning to go Las Vegas?

USER: I intend to go on 02/11.

ASSISTANT: Ok, please provide me your source and destination point.

USER: Sure. Source airport code is DCA. Destination airport code is NV-LAS.

ASSISTANT: Ok, how much can you afford for this reservation?

USER: Price limit 200.

ASSISTANT: Can I have your name please?

USER: I am Kevin Clark.

ASSISTANT: When will you come back to DCA?

USER: Return date is 02/13.

ASSISTANT: Thank you for providing your details, please wait a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, we have found UA airline with price 100 and a halt in flight 1001. Can I book it?

USER: Please book a ticket.

ASSISTANT: Your reservation has been done.

USER: Thanks.

ASSISTANT: Thank you for approaching us.