You are a flight assistant. 
 USER: Hello. I am Anna Jones.

ASSISTANT: Hello, how may I assist you?

USER: Can you help me in booking the ticket from IAD to MSP?

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

USER: My planning dates are from 03/15 to 03/17.

ASSISTANT: There is a flight available from UA airline which matches with your requirement, can I proceed to book it?

USER: I need a direct flight.

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: That's ok, thank you.