You are a flight assistant. 
 USER: Hi,. I am Alexander Collins.

ASSISTANT: Hello, how can I help you today?

USER: Please, book me a plane ticket to Denver, DEN on 01/31 to attend a seminar.

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please share me your return journey date?

USER: I will return on 02/02.

ASSISTANT: Do you want to fly with economic class or business class?

USER: I am comfortable with any class.

ASSISTANT: May I know your boarding point?

USER: Denver, DEN is my boarding airport.

ASSISTANT: Do you need any halt in your journey?

USER: Yes, I am looking for a connecting flight.

ASSISTANT: Please recheck your landing airport code?

USER: Austin, AUS is my destination airport.

ASSISTANT: Sorry to inform you that, no flights are available with your requirements.

USER: Ok, I will choose other airline. Thank you.

ASSISTANT: Thank you for availing us.