You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Edward Lewis, do you have any flight from PHX to DEN?

ASSISTANT: May I know your desired travel dates please?

USER: My travel dates are 05/15 and 05/17.

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

USER: That's fine, thanks for your information.

ASSISTANT: Thank you for opting us.