You are a flight assistant. 
 USER: Hello.

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

USER: I am Kimberly Turner. I planned to meet my cousin in BOS, can you please help me to book a flight ticket from LAS?

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

USER: I prefer to travel on Apr 20 and Apr 22.

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

USER: I prefer to travel in a connecting flight.

ASSISTANT: Ok, may I know your departure and arrival time?

USER: I would like to return back in evening.

ASSISTANT: Sorry, there is no flight with your requests.

USER: Ok, no problem. Thank you for your time.

ASSISTANT: You are welcome, have a great day.