You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: Help me in booking a flight from DTW to DEN?

ASSISTANT: Sure, I will help you. Could you please share your planned travel dates?

USER: I like to travel on June 13 to 15.

ASSISTANT: Please help me with your name for booking purpose.

USER: I am Robert Smith.

ASSISTANT: Do you need a connecting flight?

USER: No, I want direct flight.

ASSISTANT: May I know your other specifications?

USER: I prefer travelling in economy class.

ASSISTANT: Robert Smith, no flights has been found on your requirements.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.