You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Angela Williams. Can you please help me in booking a flight ticket from LGA to AUS?

ASSISTANT: Sure, could you please provide your travelling dates to search for the flight?

USER: I want to fly on Apr 16 and return on Apr 18.

ASSISTANT: Do you have any class preferences?

USER: Yes, I would like to prefer business class.

ASSISTANT: Sorry, no flight is available for you as per your requests.

USER: Not an issue.

ASSISTANT: Thank you for reaching us.

USER: Thank you.