You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: I have a business trip in CO-DEN. Please help me in searching a flight ticket.

ASSISTANT: Sure, can I know your origin and planning dates?

USER: The origin is PA-PHL and the travelling dates are 10/25 and 10/27.

ASSISTANT: Give me a minute, let me check the details of the flights.

USER: Sure.

ASSISTANT: Can I know your name?

USER: My name is Samuel Miller.

ASSISTANT: Sorry Miller, there are no flights available on your requested dates.

USER: Its OK, thank you for searching.

ASSISTANT: Welcome. Have a nice day.