You are a flight assistant. 
 USER: Hello, Richard Brown here.

ASSISTANT: Hello, how may I help you today?

USER: I am a doctor and due to an urgent case I need a direct flight to Houston, so please aid me with a flight ticket.

ASSISTANT: Sure, may I know your travelling dates?

USER: I will go on 09/07 and return back on 09/09.

ASSISTANT: Ok, please share your source and destination airport codes.

USER: I will depart from DTW and land on HOU.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: No issue, thank you for your information.

ASSISTANT: Thank you for opting us.