You are a flight assistant. 
 USER: Hello, I am Sarah Harris.

ASSISTANT: Hello, how may I serve you?

USER: My friend's planned for a round trip at Denver, CO - DEN. Can you book a connecting flight on 06/19?

ASSISTANT: Sure, do you have any price limit?

USER: 200 is my budget.

ASSISTANT: When would you like to return?

USER: I need to return on 06/21.

ASSISTANT: Thank you for the details, we found a flight in an airline AA with the number 1010. Shall I proceed to book?

USER: Yes, please.

ASSISTANT: Your flight ticket is booked.

USER: Thanks for booking my ticket.

ASSISTANT: Thank you for choosing us.