You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I best serve you?

USER: I am Ronald Young. I want to book a flight ticket from LAS to BOS. Could you help me in booking?

ASSISTANT: Sure, may I know your journey dates?

USER: My journey dates are from 05/21 to 05/23.

ASSISTANT: Do you need any other specifications?

USER: I need a halt.

ASSISTANT: Ok, please wait for a while.

USER: Ok.

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

USER: That's ok, no problem. Thank you.

ASSISTANT: Thanks for approaching us.