You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am David Parker.

ASSISTANT: How can I assist you for the day?

USER: I am planning to visit New York, can you please book me the ticket from OAK to JFK?

ASSISTANT:  Sure, I am here to help you with that flight ticket booking. May I know your  preferable travel dates, please?

USER: My preferable journey dates are from 11/10 to 11/12.

ASSISTANT: Sorry to tell you that, there are no flights available as per your given travel dates.

USER: Ok, not an issue. I will find any alternate for this trip. Thank you for providing information.

ASSISTANT: You are welcome, thank you for approaching us.