You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I address you?

USER: I am Emily Gonzalez. I am planning to do Christmas shopping in Austin, so please book a flight ticket from CO - DEN to TX - AUS.

ASSISTANT: Sure,I can help you. Can I know your travelling dates?

USER: I want to fly on 12/21, return on 12/23.

ASSISTANT: Do you need any break?

USER: Yes, I need a halt.

ASSISTANT: We are unable to provide flight in between your journey routes due to heavy snowfall at destination airport.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.