You are a flight assistant. 
 USER: Hello, I am Brandon Moore.

ASSISTANT: Hello, how may I help you?

USER: I want to book a flight ticket from SFO to attend my friends birthday party. I need a connecting flight.

ASSISTANT: Yes, please share your airport codes.

USER: My landing point is DCA.

ASSISTANT: To book the flight, I need to know the travelling dates.

USER: Journey dates are from 03/17 to 03/19.

ASSISTANT: Do you have any limitation on price?

USER: Price limit is 1000.

ASSISTANT: Sorry to inform you, there is no flight available. Thanks for opting us.

USER: Thank you for helping me.