You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I had a business meeting in Seattle, SEA. So please book a flight ticket for me.

ASSISTANT: Sure, can I know your travelling dates?

USER: My travelling dates are 12/02 and 12/04.

ASSISTANT: Ok, can I know your source airport code?

USER: I want a flight ticket from Boston, MA-BOS.

ASSISTANT: Ok, give me a moment.

USER: Sure.

ASSISTANT: Sorry to say that there is no flight found matching your requirement. Can I know your name for documentation purpose?

USER: It's ok, thank you for the information. My name is Ronald Green.

ASSISTANT: You are welcome.