You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am James Mitchell. Can you please assist me in reserving a flight ticket from Oakland to Detroit?

ASSISTANT: Sure, I will help you with that James. Can you please provide your respective airport codes?

USER: Thank you. I am willing to take off from the airport OAK and landing airport is DTW.

ASSISTANT: Please specify your planned dates of your journey.

USER: Ok, I am planning to travel in the dates of 09/15 and 09/17.

ASSISTANT: Sorry to say this James, there are no flights which can travel to your region.

USER: It's ok, not a problem with that one. Thank you for searching the flight.

ASSISTANT: Most welcome, thank you for reaching out here.