You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I am William Carter. Please search a flight ticket from AUS to DFW?

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

USER: My travelling dates are Feb 21 and Feb 23.

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

USER: I need connecting flight.

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

USER: I need my depart flight ticket at evening time and my return ticket at morning time.

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

USER: Ok, thanks for your information.

ASSISTANT: You are welcome.