You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: My name is Scott Baker. I have a business meeting in Denver, can you help me for booking a flight ticket from DEN?

ASSISTANT: Sure, Is it a round trip?

USER: Sorry, please book a ticket from AUS.

ASSISTANT: Ok. Please help me with your travel dates.

USER: Sure, my travelling dates are from 09/21 till 09/23.

ASSISTANT: Please wait a second.

USER: Sure, I will wait.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for opting us.

USER: Welcome.