You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Please book a flight ticket from LAS to LGA?

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

USER: My journey dates are July 12 and July 14.

ASSISTANT: Do you have any other requirements?

USER: I prefer a economy class.

ASSISTANT: Can I know your name please?

USER: I am Jerry Baker.

ASSISTANT: Ok, please wait.

USER: Sure.

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

USER: No problem, thank you for your information.

ASSISTANT: Most welcome.