You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am a politician, I have to meet Donald Trump at Washington DC. Could you book my ticket from San Francisco?

ASSISTANT: Sure, could you please share our departure and arrival day?

USER: My itinerary dates are Mar 21 and Mar 23.

ASSISTANT: Ok, could I have your name please?

USER: John Thomas here.

ASSISTANT: Ok, may I know your destination location airport code?

USER: My terminus airport code is DCA.

ASSISTANT: Ok, do you need direct or connecting flight?

USER: I am looking for a connecting flight.

ASSISTANT: Ok, do you have any other specifications?

USER: I want to depart from San Francisco in the afternoon.

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

USER: No problem, I will find an alternative way to travel.

ASSISTANT: Thank you for choosing us.

USER: Thank you for assisting me.