You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Kevin Moore. Can you please book a flight ticket from DTW to IAD?

ASSISTANT: Sure, I am glad to help you with the ticket booking.

USER: Thank you for your positive response.

ASSISTANT: Can you please tell me your travel dates?

USER:  I want to take off on 08/20 and please confirm my return ticket also on 08/22.

ASSISTANT: Ok, please give me a minute.

USER: Ok, take your time.

ASSISTANT: Sorry to inform you, there is no flight available in this route on the dates you have given to me.

USER: Oh! It's ok no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us. Have a nice day.