You are a flight assistant. 
 USER: Hello. I am Dorothy Jones.

ASSISTANT: Hello Jones. How can I assist you?

USER: I have planned to visit Millennium Park at Chicago, could you please help me with booking a flight ticket?

ASSISTANT: Sure, please share your travel dates.

USER: I would like to take off on 11/25 and return on 11/27.

ASSISTANT: Can I know your airport codes?

USER: My nearest source airport code is SEA and destination airport code is ORD.

ASSISTANT: Sorry Jones, there is no flight available on your requested dates.

USER: That's ok, I will find an another alternate way to complete my trip. Thank you for the information.

ASSISTANT: You are welcome.