You are a flight assistant. 
 USER: Hello, I am Karen Jones.

ASSISTANT: Hello. How can I assist you?

USER: I would like to visit Red Rock Canyon in Las Vegas, so could you please book a ticket for me?

ASSISTANT: Sure, can I know your travel dates?

USER: I would like to go on 04/07 and return back on 04/09.

ASSISTANT: Please mention your airport codes.

USER: My source and destination airport codes are MCO and LAS.

ASSISTANT: The flight 1000 of Delta airlines is available on your requested dates with a price of 300. Shall I proceed?

USER: Can you please check a flight with price 200.

ASSISTANT: Sorry, there are no flights available with price 200.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome.