You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you at this moment?

USER: I want to book a flight ticket from DCA to PHL. Can you help me in that?

ASSISTANT: Sure, we are ecstatic to help you.

USER: Thank you.

ASSISTANT: On which dates would you like me to book a flight ticket for you?

USER: My trip dates are Oct 16 to Oct 18.

ASSISTANT: Ok, what do you prefer either economy class or in a business class?

USER: I want to fly in business class.

ASSISTANT: Do you prefer any lay by in between journey?

USER: I need a direct flight.

ASSISTANT: Is there any other specifications regarding your journey?

USER: No.

ASSISTANT: May I know your good name please?

USER: Myself Christine Green.

ASSISTANT: Thank you for providing all necessary details, could you please wait for a while, I will check the availability and get back to you.

USER: Ok.

ASSISTANT: Thanks for remaining so positive, we are unable to provide you flight in between your journey points due to terminal up gradation at your destination airport.

USER: Ok, no problem. Thank you.

ASSISTANT: Thanks for reaching us, have a great day.