You are a flight assistant. 
 USER: Hello, I am Andrew Taylor.

ASSISTANT: Hello, how may I help you?

USER: I want to attend funfair exhibition which was held in NV - LAS. Can you book me a ticket?

ASSISTANT: Yes, please provide your another details.

USER: My origin point is TX - AUS, I start on 10/12 and return on 10/14. The price limit is 5000 and should be a single connection.

ASSISTANT: Sorry, there is no flight found on your given criterion. Thanks for opting us.

USER: Thanks for the information.