How do i know if my site is sandboxed?

[kjelle]

Hello i try to understand the sandbox thing but cant understand sorry, here is my test link for my website is this one sandboxed
[google.com...]

Becuse i have been on the first page for this keyword 'corfu car rental' for over 2 years, but now i am gone and i try to undestand why?

could any one out there help me to explain what is wrong with my site for the google search engine.

warm regards kjell