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

ASSISTANT: Hello, how may I aid you?

USER: I am planning to attend a flower festival at Denver, so can you book a ticket within the fare of 200?

ASSISTANT: Sure, please provide your journey points?

USER: I want to fly from New York, NY-LGA to Denver, CO-DEN.

ASSISTANT: May I know when would you like to travel?

USER: My preferred travel dates are 09/16 and 09/18.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Sorry, there were no flights found matching with your requirements.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for availing us.