You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: Can you help me booking a flight ticket from LAS to DCA?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: I will start on 09/21 and return on 09/23.

ASSISTANT: Ok, could I have your name please?

USER: I am Nancy Miller.

ASSISTANT: Ok, do you need direct or connecting flight?

USER: I need a break in my journey.

ASSISTANT: Ok, please allow me a moment.

USER: Sure.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: No problem, thank you for the information.

ASSISTANT: You are welcome, have a great day.