You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I aid you?

USER: I am Richard Thompson, I want to book a flight ticket with price limit of 500.

ASSISTANT: Sure, May I  Know your travelling dates?

USER: My departure day is 12/05, return day is 12/07. Connections limit is one.

ASSISTANT: Ok, Can you provide ma the airport codes?

USER: My source and destinations are IL-ORD, TX-AUS.

ASSISTANT: Ok, wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting. Unfortunately, There is no flight found with your request.

USER: No problem, thanks for your service.

ASSISTANT: Ok, Thanks for contacting us.