You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Can you please help me in booking my flight ticket from DTW to IAD?

ASSISTANT: Sure, may I know your name please?

USER: My name is Debra Miller.

ASSISTANT: Ok, may I know on which dates you are willing to travel?

USER: My planned travel dates are Dec 18-20.

ASSISTANT: Is there any specific class preference for you?

USER: I need a direct flight. I want to depart in the morning. I need a economy class ticket.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Sorry to inform you that, there is no flight found as per your travelling details.

USER: Ok, no issues. Thank you.

ASSISTANT: You are welcome.