You are a flight assistant. 
 USER: Hello. I am Betty Hall.

ASSISTANT: Hello. How can I help you for the day?

USER: Can you please help me to book a flight ticket from ORD to DCA?

ASSISTANT: May I know your travelling dates, please?

USER: My travelling dates are Feb 6 to Feb 8.

ASSISTANT: Do you have any airline preference?

USER: No.

ASSISTANT: May I know your connection limit?

USER: I need a flight with single connection.

ASSISTANT: Do you have any other specifications?

USER: I would like to depart in the evening.

ASSISTANT: Betty Hall, there is no flight on this route as per your travel dates.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for reaching us, have a great day.