You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you today?

USER: I am David Harris. I want to book a ticket from LAS to JFK, can you help me?

ASSISTANT: Sure, please share me your trip dates.

USER: My travel dates are 11/19 and 11/21.

ASSISTANT: Is there any class preferences for you?

USER: No.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I need a connecting flight.

ASSISTANT: Please share me your other specifications.

USER: I want to return in the morning.

ASSISTANT: Thanks for your details, please wait for a while.

USER: Sure.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: No problem, thanks for checking.

ASSISTANT: Thank you for opting us.