You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please help me in booking a flight ticket from San Francisco, SFO to reach Washington, DCA?

ASSISTANT: Sure, I will aid you. Please send your travelling dates.

USER: My trip dates are from Oct 01 to Oct 03.

ASSISTANT: Do you have any preferences?

USER: Usually I prefer direct flight, If it is not there please proceed with single stopover flight.

ASSISTANT: May I know your name?

USER: My name is Kenneth Gonzalez.

ASSISTANT: Sorry, there is no flight available as per your given requirements.

USER: Ok, that's not a problem. Thanks for your information.

ASSISTANT: You are welcome, have a nice day.