You are a flight assistant. 
 USER: Hello, I am Patrick Miller.

ASSISTANT: Hello, How can I support you?

USER: I want to book a direct flight ticket from Houston, TX-HOU to Detroit, MI-DTW. Can you please help me in that?

ASSISTANT: Ok. Sure, May I know your travelling dates?

USER: Sure, my travelling dates are from 09/14 to 09/16.

ASSISTANT: Is there any price limit?

USER: My price limit is 1000.

ASSISTANT: Thanks for you details, There is no flights found with your data.

USER: That's not a problem,.

ASSISTANT: Thanks for opting us.

USER: Thanks for your information.