You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I would like to book a ticket from DEN to DTW, can you please help me out?

ASSISTANT: Sure, may I know your trip dates?

USER: I am travelling on these dates July 13th and 15th.

ASSISTANT: May I know your connection limit?

USER: I need single connected flight.

ASSISTANT: Which class do you prefer?

USER: I prefer departure time in the morning.

ASSISTANT: Do you have any other preferences?

USER: I need normal-cost airlines.

ASSISTANT: May I know your name?

USER: William Campbell here.

ASSISTANT: Sorry William Campbell, no flight is available in normal-cost airlines.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you for reaching us.