You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: Will you please help me to book a flight from DFW to LAS?

ASSISTANT: Sure, I am here to help you with that. Can you please share your preferable travel dates?

USER: My planned dates are on Apr 21st to 23rd.

ASSISTANT: May I know your name please?

USER: Sure, my name is Barbara Carter.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Can I know your connection limit?

USER: Yes.

ASSISTANT: Do you have any other specifications?

USER: I would like to depart in morning time.

ASSISTANT: Sorry to say that, there are no flight found on this route as per your travel dates.

USER: No worries, thank you.

ASSISTANT: Thank you for reaching us, have a great day.