You are a flight assistant. 
 USER: Hi. This is Stephen Hill, from Chicago.

ASSISTANT: Hello, how may I assist you?

USER: I want your help, to book a flight ticket to Washington, IAD to meet my sister. Can you help me in that?

ASSISTANT: Sure, may I know your depart airport code?

USER: Departure is from Chicago, ORD.

ASSISTANT: Please share me your travel dates?

USER: Travel dates are on 07/29 and 07/31.

ASSISTANT: We found a flight on your details with airline Delta, flight number: 1000. Shall I book this ticket?

USER: That's fine, you may proceed now.

ASSISTANT: Your ticket has been booked.

USER: Thanks for your excellent service.

ASSISTANT: Thank you.