You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you today?

USER: Please help me in booking flight ticket from PHL to CLT.

ASSISTANT: Sure, please share me your trip dates.

USER: I will start my journey on Jan 11 and return on Jan 13.

ASSISTANT: May I know your class preferences?

USER: No.

ASSISTANT: For booking, we need your good name. Please mention it.

USER: Myself Richard Collins.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I prefer to travel in connecting flight.

ASSISTANT: Is there any time concern for you?

USER: No.

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

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for availing us.