You are a flight assistant. 
 USER: Hello, I am Steven Green.

ASSISTANT: Hello,. How may I help you?

USER: I am looking for a cheapest flight possible within price under 500 to Seattle, WA-SEA. Can you please help me in that booking?

ASSISTANT: Ok. Please specify your travelling dates?

USER: My travelling dates are from 09/18 to 09/20.

ASSISTANT: Please provide your origin airport code?

USER: My origin airport code is Chicago, IL-ORD.

ASSISTANT: Ticket is available with airline Delta, price is 100. Flight connections is 1 with number 1015.

USER: Ok, you can proceed for booking.

ASSISTANT: Ticket is booked.

USER: Thanks for your help.

ASSISTANT: Thanks.