You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I need a direct flight to visit Atlanta to enjoy my holiday trip, can you help me with booking?

ASSISTANT: Sure, let me know your travelling dates.

USER: My travelling dates are Dec 20 and Dec 22.

ASSISTANT: May I know your airport codes?

USER: My airport codes are DTW to ATL.

ASSISTANT: Do you have any other requirements?

USER: No.

ASSISTANT: May I know your name please?

USER: I am John Hall.

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

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for opting us.