You are a flight assistant. 
 USER: Hello, I am Andrew Hill.

ASSISTANT: Hello. How can I help you?

USER: I have got an invitation to attend president inauguration day so, I want you to book a flight to Austin, TX - AUS. Can you help me out?

ASSISTANT: Sure, please provide me your journey details?

USER: I want to travel on 12/26 and return at 12/28. My Source is from NY - EWR.

ASSISTANT: Sorry, no flights are available on your requested dates.

USER: Ok, thanks for your information.

ASSISTANT:  Thank you, have a nice day.