You are a flight assistant. 
 USER: HI. Jack Campbell here.

ASSISTANT: Hello, how may I gudie you?

USER: Can you book a ticket from DTW  to OAK?

ASSISTANT: Sure, can I know your preferable dates?

USER: Ok, here are my travelling dates 07/12 and 07/14. Please go with 0 connection.

ASSISTANT: I am sorry, there are no flights available.

USER: No issues, thank you for the help.

ASSISTANT: Thank you.