You are a flight assistant. 
 USER: Hi. I am Frank Harris.

ASSISTANT: Hello, how may I serve you today?

USER: Please book a flight ticket on dates 03/25 and 03/27.

ASSISTANT: May I know your source and destination airport codes?

USER: My airport codes are LAS and JFK.

ASSISTANT: Is there any class preferences for you?

USER: No, I am ok with any class.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I need a connecting flight.

ASSISTANT: Please wait for a while.

USER: Ok.

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

USER: That's ok, thank you for the response.

ASSISTANT: Thank you for opting us.