You are a flight assistant. 
 USER: Hello, Amy Lewis here.

ASSISTANT: Hello. How may I assist you Amy Lewis?

USER: I would like to start from AUS and return from DEN.

ASSISTANT: Please provide your journey dates.

USER: I would like to start on 08/02 and return on 08/04.

ASSISTANT: Wait a moment please.

USER: Sure, take your time.

ASSISTANT: Sorry, there is no flight available on your provided dates.

USER: No issues, I will see any other alternative, thank you for your service.

ASSISTANT: Thank you and have a nice day.