You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you today?

USER: I am Gary Mitchell and I want to book a flight ticket to attend my 1st cousin birthday function at Las Vegas, NV-LAS from San Francisco, CA-SFO.

ASSISTANT: Sure, could you please provide your journey dates?

USER: My travelling dates would be on 03/05 to 03/07.

ASSISTANT: We are very sorry to notify you that there is no flights available based on your details.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thanks for choosing us.