You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Charles Harris here.

ASSISTANT: How can I assist you today?

USER: I want to book a flight ticket from OAK to JFK. Can you help me in that?

ASSISTANT: Sure, can you share me your preferable dates?

USER: My trip dates are Oct 3 to 5.

ASSISTANT: Do you have any specifications?

USER: I need a connecting flight.

ASSISTANT: Sorry to inform this, no flights are available on your desired route.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you for reaching us.