You are a flight assistant. 
 USER: Hello, I am William Lee.

ASSISTANT: Hello, how may I assist you today?

USER: I want to book a ticket to Washington, DC - IAD to overview the city.

ASSISTANT: Sure, may I know your connection limit?

USER: Sure, I need a halt.

ASSISTANT: Ok, please share your journey dates.

USER: My journey dates are 04/09 and 04/11.

ASSISTANT: Ok, let me know your source point.

USER: My source is San Francisco, CA - SFO.

ASSISTANT: Unfortunately, there were no flights found on your requested dates.

USER: Ok, Thank you for your service.

ASSISTANT: Thank you for availing us.