You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How may I assist you today?

USER: Can you please book a flight ticket in business class to attend a seminar in Washington?

ASSISTANT: Sure, can you please provide me the airport codes for ticket booking?

USER: My airport codes are, SFO to DCA.

ASSISTANT: Thank you, may I know your trip dates please?

USER: My journey dates are, start from San Francisco on Dec 9th and return back on Dec 11th.

ASSISTANT: Sure, is there any another specifications on your trip, so that I can book a ticket as per your wish?

USER: Yes, I need a flight ticket under the fare of 1000. And with connecting flight.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there is no flight found with your requirement.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: May I know your name please/.

USER: My name is John Gonzalez.

ASSISTANT: Welcome, thank you for reaching us.