自动垂直居中的js

var _htmlheight;
function start(){    
    _htmlheight=document.body.scrollHeight;
    resize();
    /*$("#copyright").css({(left:$(window).width()-1000)/2+"px"});
    $("#content").css({height:$(window).height()-59-208+"px"});
    $(".inner_content").css({top:_top+"px"});
    $(window).bind('resize',function(){
    _top=($(window).height()-59-208)/2>208?($(window).height()-59-208)/2:208;
        $("#copyright").css({(left:$(window).width()-1000)/2+"px"});
        $("#content").css({height:$(window).height()+$(window).scrollTop()-59+"px"});
        $(".inner_content").css({top:_top+"px"});
    });
    $(window).bind('scroll',function(){
        $("#content").css({height:$(window).height()-208+"px"});
    });*/
    $(window).bind('resize',function(){
        resize();
    });
}
function resize(){
    var _newHeight=$(window).height()-59<_htmlheight?_htmlheight:$(window).height()-59;
    $("#content").css({height:_newHeight-208+59+"px"});
    var _contentHeight=(_newHeight-208+59-50)/2<30?30:(_newHeight-208+59-50)/2;
    $(".inner_content").css({top:_contentHeight+"px"});
    document.getElementById("copyright").style.left=($(window).width()-1000)/2+"px";
}

没注释的部分对IE6和7以外的浏览器都是有效的。为了解决IE6和7只能写固定高度。否则最小高度无效了，没空深究，先MARK。