You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Myself Richard Gonzalez. I am very interested in historical places at LGA, could you book a ticket from OAK?

ASSISTANT: Ok, may I know the travelling dates?

USER: My trip dates are 07/27 to 07/29.

ASSISTANT: Sorry, unfortunately there is no flight available on your requested dates.

USER: Ok.

ASSISTANT: Thank you for approaching us.

USER: No problem. Welcome.