You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Can you help me to book a flight ticket from SFO to CLT?

ASSISTANT: Sure, we are happy to assist you in booking. Would you like to travel in a connecting flight or a direct flight?

USER: Thank you. I prefer connecting flight.

ASSISTANT: Help me with your journey dates, so that it will be easier to move further in booking.

USER: My travel dates are Aug 23 and Aug 25.

ASSISTANT: May I know your name please?

USER: I am Helen Thomas.

ASSISTANT:  Is there any other requirements for this trip to met with, so that I can find a suitable flight for your journey?

USER: I prefer economy class flight ticket.

ASSISTANT: Ok, please wait a moment I'll search best flight for you.

USER: Sure.

ASSISTANT: Thank you for waiting, we are unable to provide flight in between your journey routes due to some technical up-gradation at destination airport.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for approaching us.