You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Can you please find a flight availability from Washington to San Francisco?

ASSISTANT: Sure, may I know your planned travel dates please?

USER: My planned travel dates are Sept 1st and Sept 3rd.

ASSISTANT: Can you please share your airport codes?

USER: The nearest airports to my desired locations are DCA and SFO.

ASSISTANT: Would you like to travel in a connecting flight or a direct flight?

USER: I am looking for a flight which is having a maximum connection limit should be at least one.

ASSISTANT: Do you have any particular time for departing and returning?

USER: I prefer to depart in the afternoon time. Apologies, I am looking for a direct flight.

ASSISTANT: May I know your good name please?

USER: My name is Rachel Lewis.

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: It's ok, not an issue with that. Anyways thank you for checking the flight availability.

ASSISTANT: You are welcome.