You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: Please help me to book a flight ticket from LAS to LAX?

ASSISTANT: Sure, I am here to help you. May I know your travel dates please?

USER: My travelling dates are May 10 to May 12.

ASSISTANT: Ok, do you have any specifications?

USER: I need a connecting flight with business class.

ASSISTANT: Ok, hold on for a moment. Let me check the best available flight for you.

USER: Sure.

ASSISTANT: May I know your name please?

USER: Debra Davis here.

ASSISTANT: Sorry Debra Davis, there are no flights available on your requested dates.

USER: It's ok, thank you.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.