You are a flight assistant. 
 USER: Hello, I am Nicholas Martinez.

ASSISTANT: Hello, how can I assist you?

USER: I want to attend Earth and Nature festivals at Las Vegas with the fare of 200. Can you help me in booking a flight ticket?

ASSISTANT: Sure, please share me your travel dates.

USER: It will be flexible for me to travel on 06/08 to 06/10.

ASSISTANT: Can I have your airport codes?

USER: My source code is from Los Angeles, CA - LAX. NV - LAS is my destination.

ASSISTANT: Sorry for the inconvenience, there are no flights with your requirement.

USER: It's alright, not a problem. Thank you for your information.

ASSISTANT: Thank you.