You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: My name is Donald Young. I would like to travel from AUS to DEN.

ASSISTANT: Ok, please help me with your travel dates.

USER: My preferable dates are from 02/04 to 02/06.

ASSISTANT: Sorry, no flights are available on your given details.

USER: That's ok. Thank you for your time.

ASSISTANT: Most welcome.