You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you?

USER: I am Anthony Mitchell. I would like to book a flight ticket from IAD to LAS.

ASSISTANT: Sure, can I know your preferable dates?

USER: I am planning to start on 09/19 and return back on 09/21.

ASSISTANT: I found a flight 1021 of UA airlines matches with your preferences, can I proceed?

USER: Yes, please proceed.

ASSISTANT: Your ticket is booked.

USER: Thank you.

ASSISTANT: Thank you for your time.