You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am Charles Miller. I would like to book a ticket to Austin, can you please help me out?

ASSISTANT: Sure, can you please let me know your travel dates?

USER: My travelling dates are 11/25 and 11/27.

ASSISTANT: Miller, may I know your airport codes?

USER: I am flying from DTW to AUS.

ASSISTANT: Ok, please wait for sometime. I will check for the best flight.

USER: Sure.

ASSISTANT: Sorry Miller, there are no flights available on your preferred dates.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you so much for contacting us and have a nice day.