You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Lisa Lewis here.

ASSISTANT: How can I assist you?

USER: I would like to meet my brother at Boston, please help me in booking a ticket from AUS to BOS.

ASSISTANT: Sure Lisa, can I know the travel dates please?

USER: My travel dates are 12/26 and 12/28.

ASSISTANT: Ok, wait a moment please.

USER: Sure, take your time.

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

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for approaching us.