You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Ryan Perez.

ASSISTANT: Ryan, how may I assist you?

USER: Actually, I am planning to visit my cousin's birthday party, so I want to go from DEN to AUS. Can you help me out?

ASSISTANT: Convey my wishes to your cousin. Sure, I can help you to book your ticket.

USER: My starting date is 09/14 and returning  date is 09/16.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Sorry, I could not find a flight from DEN to AUS on your preferred dates.

USER: That's fine. Thank you for your help.

ASSISTANT: Thank you for approaching us.