You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I am looking to reserve a flight ticket to reach Las Vegas, can you please find a flight with the connection limit 1?

ASSISTANT: Sure, may I know your airport codes please?

USER: The preferred airport codes are DFW and LAS.

ASSISTANT: Thank you, may I know your planned travel dates?

USER: The scheduled travel dates are Dec 19 and Dec 21.

ASSISTANT: Do you have any class preference?

USER: I need a business class flight to reach my destination.

ASSISTANT: May I know your name for booking purpose?

USER: My name is Timothy Collins.

ASSISTANT: Do you want any another specifications?

USER: No, I have mentioned all my specifications.

ASSISTANT: Unfortunately, no flights available on your requirements.

USER: It's ok, not a problem with that. Anyways thank you for your time.

ASSISTANT: Welcome, thank you for reaching us.