You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you at this moment?

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

ASSISTANT: Sure, could I have your trip dates, please?

USER: My travelling dates are Aug 19 to Aug 21.

ASSISTANT: May I know your good name?

USER: Richard Evans.

ASSISTANT: Do you have any specifications?

USER: I need a single connection of flight. I want to return in the morning.

ASSISTANT: Sorry, there are no flights available as per your requirements.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for choosing us.