You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. In which way I can aid you at this moment?

USER: Emma Lopez here. I want to book a ticket from JFK to LAS.

ASSISTANT: Sure, I am happy to aid you in booking flight ticket. Can you please let me know your preferable travel dates for booking flight ticket?

USER: My trip dates are 03/25 and 03/27.

ASSISTANT: Ok, please wait a moment, I will check flight availability in this route.

USER: Sure.

ASSISTANT: We regret to inform you that there are no flights found on your route with your planned dates of travelling.

USER: Its ok, no problem. Anyways thank you.

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