You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

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

ASSISTANT: Sure, may I know your trip dates please?

USER: My trip dates are June 21 and June 23.

ASSISTANT: Do you have any other requirements?

USER: I need a connecting flight which departs in the afternoon.

ASSISTANT: Can I know your name please?

USER: Laura Edwards here.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: It's ok, thank you.

ASSISTANT: Most welcome.