You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, What kind of help are you expecting from our side?

USER: I am William Thompson. I want to book a flight ticket from BOS to LAS. Could you help me in booking?

ASSISTANT: Sure, may I know your preferable dates of journey please?

USER: My travelling dates are from June 10-12.

ASSISTANT: Do you like to go with a economy class or business class?

USER: I am comfortable with both.

ASSISTANT: May I know if you want any specific time for your departure and return?

USER: My return time should be in the evening.

ASSISTANT: Do you prefer any way station in between journey?

USER: Yes, I need connecting flight.

ASSISTANT: Thanks for your details, sorry to inform you that unfortunately there is no flights available by the given details.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thanks for approaching us, wish you a great day.