You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: I want to book a flight ticket from IAH to IAD. Could you help me in booking?

ASSISTANT: Sure, May I know the travelling dates?

USER: My travelling dates are from Dec 31 to Jan 02.

ASSISTANT: Do you have any connection limit?

USER: I prefer for connecting flight.

ASSISTANT: Is there any other requirements?

USER: My return time should be in the afternoon.

ASSISTANT: May I know your name?

USER: Helen Campbell.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you for availing us.