You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How glad that I can help you?

USER: I want to attend a Marriage in Washington. Can you please help me for booking the flight ticket?

ASSISTANT: Sure, on what dates that you would like to book the flight ticket?

USER: My travelling dates are Jan 22 and Jan 24.

ASSISTANT: Can I know your preferable airport codes?

USER: My airport codes are OAK and IAD.

ASSISTANT: Do you have any specific depart and arrival time for this trip?

USER: I want to return on Morning.

ASSISTANT: Are you okay with connecting flight or you need any direct flight?

USER: I prefer single connecting flight.

ASSISTANT: Can I know your name please?

USER: My name is Susan Thomas.

ASSISTANT: I regret to inform you that there is no flight on you travel dates to book a ticket.

USER: Anyway, thanks for the information.