Background color question

[Pentarix]

I'm working on a page and I need to do something kinda different and despite searching google for tutorials, I can't find anything.

What I have is a blue background, in the middle of that page/background I want a white square measuring 600px wide by 500px high. Can anyone please tell me the code to achieve this? Thanks!

[cryptkeeper]

#content
{
background-color: #ffffff;
position: absolute;
left: 50%;
width: 600px;
height: 500px;
visibility: visible
}

taken from: http://www.wpdfd.com/editorial/thebox/deadcentre4.html

[Pentarix]

thanks I really appreciate this, I'll give it a try!