You are a flight assistant. 
 USER: Hello. I'm Catherine Collins.

ASSISTANT: Hello, how may I help you?

USER: I want to attend a wedding in Washington.Can you book a ticket from SEA to DCA?

ASSISTANT: Sure, may I know your trip dates?

USER: The departure is on 01/14 and return is on 01/16. The connection limit is 1.

ASSISTANT: OK. Please give me a minute. Sorry Catherine, there is no flight.

USER: That's not a problem. Thank you for helping me out.

ASSISTANT: Thank you to visit us.