You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Can you book a flight ticket from SEA to IAD?

ASSISTANT: Sure, May I know your journey dates?

USER: I want to take off on Nov, 20 and return back on Nov, 22.

ASSISTANT: Do you have any connection limit?

USER: I need single connection.

ASSISTANT: Is there any airline preference?

USER: Yes, It is normal cost airlines.

ASSISTANT: Do you have any other preference?

USER: No.

ASSISTANT: May I know your good name?

USER: Sure, myself Joseph Davis.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry, we found no flights on your preferred dates.

USER: It's ok, not an issue. Thank you.

ASSISTANT: Thank you for choosing us.