You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I am Ryan Thompson, can you find a direct flight for me?

ASSISTANT: May I know your desired travel dates please?

USER: Ok, my trip dates are from 09/09 and 09/11.

ASSISTANT: Can I know your desired airport codes please?

USER: Fine, my locations are from HOU to ORD.

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

USER: It's ok, thanks for your information.

ASSISTANT: Thank you for opting us.