You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Carol Jackson here. I want to attend a Shuttle competition in Detroit, MI-DTW. Can you please help me for booking the flight ticket?

ASSISTANT: Sure Carol, I will help you in booking your ticket. Can you please provide your travelling dates?

USER: My departure date is 06/21 and return date is 06/23.

ASSISTANT: May I know your departure airport code?

USER: My origin airport code is AZ-PHX. Make sure my price limit is 200.

ASSISTANT: Ok, please wait a moment.

USER: Ok, take your time.

ASSISTANT: Sorry, there no flights found on these dates.

USER: So sad for that. Anyway, thank you for the information.

ASSISTANT: Thank you for choosing our services.