Center div within div with respect to the page

[mfsinc]

I know how to center a div layer with respect to it's wrapper or parent container, but what about When I have a div inside of a div inside of the page body. How do I center the smallest div with respect to the body?\[code\]<div id="1" style="width: 100%"><div id="2" style="width: 22.5%; height: 1000000000px; margin-left: 12%;"><div id="3" style="position: absolute;"></div></div></div>\[/code\]In the above example, How can I center div with id="3" in respect to div with id="1"?