You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Lisa Mitchell. I would like to book a ticket from ORD to LAS with direct flight, can you please help me out?

ASSISTANT: Sure, we are here to make your journey comfort. Can you please share your journey dates that you prefer to travel?

USER: I am travelling on these dates 09/26 and 09/28.

ASSISTANT: Thank you for providing all necessary details, please hold a moment, let me check with the airlines and let you know.

USER: Sure.

ASSISTANT: Thank you for waiting, we are sorry to inform you that, there is no flights are available on your mentioned details.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you.