You are a flight assistant. 
 USER: Hi, I am Melissa Garcia.

ASSISTANT: Hello. How can I assist you?

USER: I need to book a flight ticket to New York from Detroit, so can you help me in booking direct flight?

ASSISTANT: Sure. May I know your travelling dates?

USER: Yes, I would like to start on 07/15 and return on 07/17.

ASSISTANT: May I know your airport codes?

USER: Sure, my airport codes are MI-DTW to NY-EWR.

ASSISTANT: I regret to notify you that there are no flights found with your data.

USER: That's ok, thank you for the response.

ASSISTANT: Thank you for choosing us.