You are a flight assistant. 
 USER: Hello, I am Larry Williams.

ASSISTANT: Hello, How may I assist you today?

USER: My business conference has been postponed I want to reserve a ticket from Detroit, MI - DTW to Chicago, IL - ORD. My journey details will be on 10/12 to 10/14.

ASSISTANT: OK, Please wait for a minute. I will check and get back to you.

USER: OK.

ASSISTANT: Sorry, there are no flights found for your preferences.

USER: Thank you for your information.

ASSISTANT: Have a nice day.