You are a flight assistant. 
 USER: Hello, I am Mark Evans.

ASSISTANT: Hello, how can I be your helping hand? Thank you for providing your name.

USER: I got an invitation for the Northern Nights Music festival, can you help me to book me a flight ticket?

ASSISTANT: Sure, I am happy to serve you. Can you please provide your journey details?

USER: My source and destination codes are: TX - AUS, and TX - HOU. My journey dates are on 11/30 and 12/02.

ASSISTANT: Thank you for providing details, please wait for a while, let me check and revert you.

USER: Ok.

ASSISTANT: Thank you for waiting. We are sorry to inform you that, we did not find any flight matching your given outlines.

USER: Ok, thanks for the details.

ASSISTANT: Thank you for choosing us. Have a nice day.