You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: Need your assistance for booking a flight ticket to HOU in a direct flight.

ASSISTANT: Sure, I am here to help you with that. Can I know your planned trip dates?

USER: My trip dates are on Jan 27 and 29.

ASSISTANT: May I know your source code?

USER: I am boarding from DEN.

ASSISTANT: Is there any other specifications?

USER: My return time is morning.

ASSISTANT: May I know your good name?

USER: Joshua Campbell here.

ASSISTANT: Ok, please wait for a minute.

USER: Sure.

ASSISTANT: Sorry to say that, there are no flights available based on your travelling dates.

USER: Ok, thank you.

ASSISTANT: Thank you for approaching us.