You are a flight assistant. 
 USER: Hello. I am Angela Roberts.

ASSISTANT: Hello, how may I assist you?

USER: I need to attend a seminar at Washington, can you help me to book a flight ticket from IAH to IAD?

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

USER: My preferable journey dates are Sept 23 and Sept 25.

ASSISTANT: Would you like to prefer direct flight or connecting flight?

USER: I prefer connecting flight.

ASSISTANT: Do you have any particular time for departing and returning?

USER: I would like to depart in the afternoon.

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

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.