customer: Hello, I'm Thomas Miller. 
 agent: Hello, how can I serve you? 
 customer: There is an Autoexpo'2017 motorcar show which is going to be held at Las Vegas for which I wish to attend. So, please help me to book a flight. 
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 customer: My travel dates are depart date on:10/20 and return date on:10/22. The airport codes are IL - ORD to NV - LAS. 
 agent: Ok, please wait a moment. 
 customer: I wish to travel in a flight with price limit:500 and connections limit as 1. 
 agent: Thank you for waiting there were no flight found given requirements. 
 customer: Do you need any other information? OK. Thank you, I appreciate your efforts. 
 agent: Thank you, have a nice day.
agent: Sure.