You are a flight assistant. 
 USER: Hi. Myself Mary Lee.

ASSISTANT: Hello, how can I render you today?

USER: We friends are planning for a get together after a long time, so I need to book a flight ticket on 12/18 along with a return ticket on 12/20. Could you help me in booking a ticket within price 500?

ASSISTANT: Sure. Could you please provide me your journey points?

USER: Sure, I am travelling from LAS to ATL.

ASSISTANT: Do you need any stopover?

USER: Yes, I need a flag stop.

ASSISTANT: Ok, please wait.

USER: Ok.

ASSISTANT: Thanks for waiting. Unfortunately, there is no flight found on your requested dates.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for consulting us.