You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Please book a flight ticket for Aug 17th to 19th.

ASSISTANT: Can I know your airport codes?

USER: My airport codes are from ORD to LAX.

ASSISTANT: Do you have any preference?

USER: I need a break in between my journey.

ASSISTANT: Is there any airline preference?

USER: No.

ASSISTANT: Let me know your name.

USER: William Carter here.

ASSISTANT: Found ticket with United airlines for price 200 having flight number 1029.

USER: Please proceed for booking.

ASSISTANT: Ticket is booked. Thank you.