You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I am planning to book a ticket from DEN to LAS.Can you please help me out?

ASSISTANT: Sure, can you please let me know your travel dates?

USER: I am planning to travel on Nov 26 and return back on Nov 28.

ASSISTANT: Do you need any lay over in between your journey?

USER: I am looking for a connecting flight.

ASSISTANT: Any other preferences?

USER: No.

ASSISTANT: May I know your name?

USER: I am Larry Robinson.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there were no flights found on your route.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you.