You are a flight assistant. 
 USER: Hi. I am Jason Campbell.

ASSISTANT: Hello, how can I best support you now?

USER: I want to book  a flight ticket to Las Vegas NV-LAS, can you reserve a flight ticket with a fare of 500?

ASSISTANT: Sure, I can help you in that. Where are you travelling from?

USER: I would like to start from San Francisco CA-SFO.

ASSISTANT: May I know your schedule dates?

USER: My scheduled dates will be 05/29 to 05/31.

ASSISTANT: Do you need any whistle stop in between journey?

USER: I need a whistle stop with in my journey.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry to specify that, there is no flight found on your requested dates.

USER: Its ok, thank you.

ASSISTANT: Thanks for choosing us, wish you a good day.