You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am looking to book a flight ticket to meet my friend in Washington, can you help me for booking a flight ticket from IAH to IAD?

ASSISTANT: Sure, may I know your planned travel dates please?

USER: My travelling dates are Oct 14 and Oct 16.

ASSISTANT: Do you have any class preference?

USER: My class preference is business.

ASSISTANT: Would you like to travel in a connecting flight or a direct flight?

USER: I need a single connecting flight.

ASSISTANT: May I know your good name please?

USER: My name is Brandon Green.

ASSISTANT: Do you have any other specifications?

USER: No.

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for approaching us.