You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you for today?

USER: Eric Evans here. I would like to book a ticket from LAS and VAS.

ASSISTANT: Sure, I am glad to help you with that. Can you please provide your planned dates of journey?

USER: My itinerary travel dates are Nov 21 and Nov 23.

ASSISTANT: Could you please confirm your destination code?

USER: sorry, My fault. LAS and AUS.

ASSISTANT: Please wait to check the available flight for your journey.

USER: Sure.

ASSISTANT: I regret to say this Eric Evans, there are no flights on your planned dates of journey.

USER: No problem, Thank you for your time.

ASSISTANT: You are welcome, thank you for reaching us.