Centering content vertically and horizontally, the browser doesn't allow scrolling

[nextox]

I'm using the following css to center my content both vertically and horizontally; the problem is that when you minimize the browser to make it smaller than the content \[code\]div\[/code\], it continues to center but without the ability to scroll. The content just cuts off at the top.\[code\]#splash-centre-container{ position: absolute; top: 50%; left: 50%; height: 550px; width: 760px; min-height: 550px; padding: 20px; margin: -310px 0 0 -400px;}\[/code\]