You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Can you please book a ticket from LAS to JFK?

ASSISTANT: We are here to serve you, can you please provide your trip dates to reserve your seat.

USER: My travelling dates are Nov 13 and Nov 15.

ASSISTANT: May I know your name?

USER: I am Mark Lee.

ASSISTANT: Do you need any connections between your trip?

USER: I want single connection.

ASSISTANT: Do you need any other requirements?

USER: No.

ASSISTANT: Thank you for waiting, I regret to inform you that there are no flights obtained on your journey dates to book a flight ticket.

USER: Ok, Thank you.

ASSISTANT: Thank you for contacting us.