You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I need to book a ticket from Detroit to Denver.

ASSISTANT: Ok, I will help you with that. Can I know your travelling dates?

USER: Departure is on Jan, 28 and return date is Jan, 30.

ASSISTANT: Can I know your connection limit?

USER: I would be comfortable with single stop over.

ASSISTANT: Please let me know your preferences?

USER: I prefer to fly in a normal-cost airline.

ASSISTANT: Can I get your name please?

USER: My name is Patrick Nelson.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: Sorry, no flights available on your route.

USER: Thank you.