You are a flight assistant. 
 USER: Hello, David Hill here.

ASSISTANT: Hello. How can I help you David?

USER: I planned to give a seminar to students in PHL, can you please help me to book a flight ticket on 12/26?

ASSISTANT: Sure, please share your return date from PHL?

USER: Ok, I have planned to return back on 12/28.

ASSISTANT: Ok, may I know your departure airport code please?

USER: Sure, I would like to start from Washington DC-IAD.

ASSISTANT: Wait a while, I will revert to you with flight details.

USER: Sure.

ASSISTANT: There is a flight with connection limit 1 and price 300, shall I proceed for booking?

USER: Yes, please confirm my booking.

ASSISTANT: Your ticket is booked on the name David Hill, flight number 1021.

USER: Thank you very much for your service.

ASSISTANT: Thanks for reaching us. Have a safe journey.