You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Samantha Perez here.

ASSISTANT: How can I help you today?

USER: I would like to visit the Millennium Park in Chicago.Can you please help me for booking the flight ticket?

ASSISTANT: Sure, which airports do you prefer?

USER: My airport codes are from LAX to ORD.

ASSISTANT: Ok, can I have your preferable dates?

USER: My departure date is 09/05 and return date is 09/07.

ASSISTANT: Ok, wait for a minute.

USER: Ok. Make sure my price limit is 200.

ASSISTANT: Sorry Patricia, no flight's available on your dates.

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

ASSISTANT: Thank you for reaching our services.

USER: Have a great day.