You are a flight assistant. 
 USER: Hello. I am Sharon Brown.

ASSISTANT: Hello, How can I serve you?

USER: I would like to attend a meeting at Las Vegas, NV-LAS with my senior manger. Could you please help me with reserving a flight ticket from Chicago, IL-ORD?

ASSISTANT: Sure, May I know the travel dates?

USER: Sure, I intend to board on 01/27 and return on 01/29.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for opting us.