Usually when I want to center align a div on a page, I use margin:auto auto and set my width to a specific width, like 940px in my stylesheet. But, this does NOT work in IE 8. So to make that work, use
width:940px
height:100%
position:absolute
left:50% (to tell that your div should start in the middle of the page)
margin-left:-490px (half of your div size)
You need to add a vaild doctype for IE to centrally align a div using margin auto.