You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you help me in doing a reservation from LAS to LAX?

ASSISTANT: Sure, may I know the travelling dates?

USER: My trip dates are Dec 23 to 25.

ASSISTANT: Do you have any connection limit?

USER: I need a connecting flight.

ASSISTANT: Is there any other requirements?

USER: Please ensure that my depart time must be evening.

ASSISTANT: May I know your name?

USER: Charles Evans here.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, no flights found with your chosen dates.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for availing us.