网页垂直居中、Div水平垂直居中
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
<script type="text/javascript">
function bgCenter() {
var HeightDifference = document.documentElement.clientHeight - 580;
var ScreenWidths = document.documentElement.clientWidth;
if (HeightDifference > 0) {
document.getElementById("DivBg").style.marginTop = HeightDifference / 2 + "px";
}
else {
document.getElementById("DivBg").style.marginTop = "0px";
}
if (ScreenWidths <= 968) {
document.getElementById("DivBg").style.width = "968px";
}
else {
document.getElementById("DivBg").style.width = "100%";
}
if (ScreenWidths > 968) {
document.getElementById("login").style.left = ScreenWidths / 2 - 326 + "px";
}
else {
document.getElementById("login").style.left = "158px";
}
}
</script>
</head>
<body onload="bgCenter()" onresize="bgCenter()">
<div style="width:100%; height:580px; position:relative; background-color:#000000;" id="DivBg">
<div style="position:absolute; width:652px; height:423px; top:79px; background-color:#ff0000;" id="login">
</div>
</div>
</body>
</html>
