You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hellio. How may I assist you today?

USER: Jeffrey Hernandez here. I want to book a ticket from PHL to DTW. Could you help me?

ASSISTANT: Sure, we can help you with it. Let me know your planned travelling dates?

USER: Thank you. My preferable dates are from 03/19 to 03/21.

ASSISTANT: Thank you for your details, there are no flights found with your specified travelling dates.

USER: That's ok, no problem. Thank you for helping me.

ASSISTANT: Thank you.