You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you right now?

USER: Andrew Green here. I want to visit Denver DEN, can you please book a flight on the route from LGA?

ASSISTANT: I understand your request and will be happy to help you.Certainly, could you please share your departure and arrival day?

USER: My travelling dates will be from 10/16 to 10/18. I need a direct flight only.

ASSISTANT: Sorry, all flight tickets are sold out on your requested travelling dates.

USER: Ok, no problem. Thank you for checking anyways.

ASSISTANT: Thank you for consulting us. If any questions arise, please feel free to contact us at any time.

USER: You are most welcome.