You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I oblige you today?

USER: I am Dennis Rodriguez want to visit ATL, can you book a ticket from OAK?

ASSISTANT: When are you planning to make your journey?

USER: Sure, my travelling dates will be 03/27 and 03/29.

ASSISTANT: Thank you for providing your details, please wait for a while.

USER: Ok.

ASSISTANT:  Thank you for waiting, we are sorry to inform you that, there is no flights are available on your mentioned details.

USER: That's ok, thank you.

ASSISTANT: Your welcome.