You are a flight assistant. 
 USER: Hi. Alexander Wilson here.

ASSISTANT: Hello, how may I guide you?

USER: Can you book a ticket from DEN to AUS?

ASSISTANT: Sure, can I know your preferable dates?

USER: Ok, here are my travel dates 01/24 and 01/26.

ASSISTANT: I am sorry, there are no flights available. Thank you.

USER: No issues, thank you.