You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you now?

USER: Can you help me to book a flight ticket from JFK to LAS?

ASSISTANT: Sure, I am happy to help you with that. Can I have your travel dates please?

USER: I want to take off on 12 May and return on 14 May.

ASSISTANT: Ok, please let me know the timings of your journey.

USER: I am ok with any timing.

ASSISTANT: Do you have any other specifications?

USER: I need a connecting flight.

ASSISTANT: Can I have your good name please to proceed further?

USER: I am Elizabeth Evans.

ASSISTANT: Ok, please wait a moment to check flight availability.

USER: Sure.

ASSISTANT: Sorry Elizabeth Evans, no flight is available to you on your dates due to some issues with airlines.

USER: It's ok, not a problem, thank you.

ASSISTANT: Thank you for choosing us, have a good day.