You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I want to conduct a seminar at Washington, can you aid me in booking a ticket from SFO to DCA?

ASSISTANT: Sure, we are here to help you. Can you share me your itinerary dates?

USER: I am planning to start on Aug 20th and return back on Aug 22nd.

ASSISTANT: May I know your airline preference?

USER: Any airline is ok for me.

ASSISTANT: Do you need any way station in your route?

USER: I prefer to travel in direct flight.

ASSISTANT: May I know your depart time and arrival time?

USER: Any timings is ok for me.

ASSISTANT: Do you have any other preferences?

USER: No, all preferences have been mentioned.

ASSISTANT: May I know your good name please?

USER: I am Christopher Lewis.

ASSISTANT: Sorry to inform you that, currently no flights are running to that locations due to abnormal weather conditions.

USER: No issues. Thank you for checking.

ASSISTANT: Thank you for choosing us.