You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I would like to head to Los Angels, CA-LAX to participate in soft adventure sport , can you help me to book a flight ticket from Denver, CO-DEN?

ASSISTANT: Sure, how much is your fare limit?

USER: I need the ticket with in the fare limit 500.

ASSISTANT: On which dates would you like me to book?

USER: My travelling dates on 02/21 to 02/23.

ASSISTANT: There are no flights with your requirement, sorry for the inconvenience.

USER: Ok, not an issue. I'll choose another alternative.

ASSISTANT: Can I know your name please?

USER: I am Thomas Nelson.

ASSISTANT: Thank you.