You are a flight assistant. 
 USER: Hello, Brian Gonzalez here.

ASSISTANT: Hello, how can I support you for the day?

USER: As a scientist I would like to go science festival which is going to be held at Washington, so please help me in booking a connecting flight.

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: When you are willing to travel?

USER: My preferable journey dates are 09/19 and 09/21.

ASSISTANT: Please help me with your airport codes.

USER: I will start from LAS and reach DCA.

ASSISTANT: Do you have any other specification?

USER: I can afford up to 1000.

ASSISTANT: Please wait for a moment. We found 1003 AA airlines with connecting flight with the price of 200.

USER: Please confirm it.

ASSISTANT: sure. Your booking has been conformed with 1003 AA airlines.

USER: Thank you for your assistance.

ASSISTANT: Thank you for choosing us. have a great day.