You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Joseph Carter.

ASSISTANT: How can I aid you today?

USER: I am looking to book a flight ticket from AUS to IAD to meet my friend. Can you help me for booking a flight ticket?

ASSISTANT: Sure, I am here to help you in booking. Can you please share your travel dates?

USER: My travelling dates are 12/11 and 12/13.

ASSISTANT: Please wait a moment.

USER: Sure, I will wait for your response.

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

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for opting us, have a nice day.