You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to watch tennis match at New York, so please book my ticket from Denver.

ASSISTANT: Sure, may I know your trip dates?

USER: My itinerary dates are May 8 and May 10.

ASSISTANT: Can I know your destination airport code please?

USER: My terminus airport code is LGA.

ASSISTANT: Do you have any other requirements?

USER: I prefer to travel in business class.

ASSISTANT: Can I know your name please?

USER: Richard Lopez here.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: No problem, thank you.

ASSISTANT: Most welcome.