You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: can you please help me with booking a flight ticket from HOU to CLT?

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

USER: My travelling dates are from Jun 10-12.

ASSISTANT: Do you have any other requirements?

USER: I prefer business class.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Can I know your name please?

USER: Sure, Lisa Wilson here.

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

USER: No problem, thank you for the information.

ASSISTANT: Most welcome.