You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Robert Moore here. Can you please book a flight ticket from OAK to IAD?

ASSISTANT: Sure, may I know your planned travel dates please?

USER: Sure, my trip dates are from 11/13 to 11/15.

ASSISTANT: There is a direct flight available on your requested dates from UA airlines.Shall I confirm your booking?

USER: Can you please search for connecting flight?

ASSISTANT: Sorry, there is no flight available for your request.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: You are welcome.