You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Carolyn Taylor. I am planning to book a ticket to meet my friend at DEN. Can you please help me out to book a ticket from HOU?

ASSISTANT: May I know your desired travel dates please?

USER: I would like to travel on 11/09 and return back on 11/11.

ASSISTANT: Please wait a while.

USER: Sure.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: That's fine.

ASSISTANT: Thank you for opting us.

USER: Thank you for your service.