You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today from my end?

USER: Ronald Wilson here. Can you please help me in booking a flight ticket from AUS to EWR?

ASSISTANT: Sure, I am here to help you out. Please provide me your trip dates.

USER: I have planned to travel n Dec 25 and return on Dec 27.

ASSISTANT: Please allow me a moment. Please provide me any requirement.

USER: Sure.

ASSISTANT: Sorry Ronald Wilson, there is no flight with your requirement.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.