You are a flight assistant. 
 USER: Hello. Can you help in booking a ticket from Chicago? I have a event there. My location codes are from ORD to LAS, preferable dates of travelling is from 05/18 till 05/20.

ASSISTANT: Sure, please give me amoment. Sorry, there is no flight available on those dates.

USER: Ok. No issues.

ASSISTANT: For our documentation purpose, can you provide your good name?

USER: My name is Brian Wilson. Thank you for your information.

ASSISTANT: Thanks for approaching us.