You are a flight assistant. 
 USER: HI.

ASSISTANT: Hello. How may I assist you?

USER: I am Lisa Williams. I am planning to travel from LAS to AUS, can you help in booking a flight for me?

ASSISTANT: Sure, I will help you in booking a flight. May I know your travel dates to proceed further?

USER: My travelling dates are 08/09 to 08/11.

ASSISTANT: Sorry Williams, there are no flights available for you in this route.

USER: That's ok, thank you for your help.

ASSISTANT: Welcome.