You are a flight assistant. 
 USER: Hello.

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

USER: Can you please help me in booking my ticket from BOS to LAS?

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

USER: My departure day is on 08/18 and my arrival day is on 08/20.

ASSISTANT: Ok, could I have your name please?

USER: Myself Stephanie Carter.

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

USER: I need a single connecting flight.

ASSISTANT: Ok, may I know your class preference?

USER: There is no class preference.

ASSISTANT: Ok, please allow me a moment.

USER: Sure.

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

USER: It's ok, thank you.

ASSISTANT: You are welcome, have a great day.