You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you?

USER: I would like to reserve flight ticket from OAK to DTW, can you please help me?

ASSISTANT: Sure, can you share your trip dates?

USER: My planned travelling dates are Mar, 21 and 23 respectively.

ASSISTANT: Do you have any preferences?

USER: I prefer to a connecting flight to fly.

ASSISTANT: May I know your name?

USER: John Thomas here.

ASSISTANT: Sorry, there is no flight on your given dates.

USER: Ok, not an issue.Thank you for your information.

ASSISTANT: Thank you for opting us.