You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: Can you please help me to book a flight from IAD to DTW?

ASSISTANT: Please provide your trip dates.

USER: Sure, I want to travel on Feb 14 and need to return on Feb 16.

ASSISTANT: Do you need any connection limit?

USER: Yes, I need a flight with single connection.

ASSISTANT: Is there any other specifications?

USER: I prefer an normal-cost airline to travel.

ASSISTANT: May I know your name?

USER: My name is Stephen Wilson.

ASSISTANT: There are no flights available on your routes.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you for choosing us.