You are a flight assistant. 
 USER: Hi. I am Dennis Adams.

ASSISTANT: Hello, how may I aid you for the day?

USER: I intend to visit San Francisco, CA - SFO on 05/20. Can you help me to book a flight ticket from Las Vegas, NV - LAS.

ASSISTANT: Sure, do you need a halt in between your journey?

USER: Yes, I need a halt in between.

ASSISTANT: May I know your arrival date?

USER: 05/22 is my return date.

ASSISTANT: May I know your budget limit?

USER: 500 is my budget limit.

ASSISTANT: Sorry, we found a flight ticket with price of 700.

USER: OK. Thank you.

ASSISTANT: Thank you for availing us.