document.body.clientWidth 1004 客户端浏览器的宽度
document.body.clientHeight 598 客户端浏览器的高度
document.body.scrollLeft 0 若有滚动条，则代表距左端的距离
document.body.scrollTop 0 若有滚动条，则代表距上端的距离
document.body.scrollWidth 1004 若有滚动条,滚动条的宽度
document.body.scrollHeight 652 若有滚动条,滚动条的高度
screen.height 取分辨率用
screen.width
测试页面：
<html><head></head><body><input id="btn" type="button" onclick="Test();"/></body><script language='javascript'>
alert(screen.width);
alert(screen.height);
function Test()
{
alert(document.body.clientWidth);
alert(document.body.clientHeight);
}
</script></html>
下面代码是一个例子，在页上走动的小广告
<DIV id="img" style="LEFT: 0px; WIDTH: 99px; POSITION: absolute; TOP: 1582px; HEIGHT: 24px">
<img src="images\ask.gif" width="50" height="50">
</DIV>
<SCRIPT language="JavaScript">
var xPos = 20;
var yPos = document.body.clientHeight;
var step = 50;
var delay = 2000;
var height = 0;
var Hoffset = 0;
var Woffset = 0;
var yon = 0;
var xon = 0;
var pause = true;
var interval;
img.style.top = yPos;
function changePos() {
alert(document.body.clientHeight);
alert(document.body.clientWidth);
alert(document.body.scrollLeft);
alert(document.body.scrollTop);
alert(document.body.scrollWidth);
alert(document.body.scrollHeight);
//alert(Hoffset);
//alert(Woffset);
width = document.body.clientWidth;
height = document.body.clientHeight;
Hoffset = img.offsetHeight; //不变54
Woffset = img.offsetWidth; //不变99
img.style.left = xPos + document.body.scrollLeft;
img.style.top = yPos + document.body.scrollTop;
if (yon) {
yPos = yPos + step;
} else {
yPos = yPos - step;
}
if (yPos < 0) {
yon = 1;
yPos = 0;
}
if (yPos >= (height - Hoffset)) {
yon = 0;
yPos = (height - Hoffset);
}
if (xon) {
xPos = xPos + step;
}
else {
xPos = xPos - step;
}
if (xPos < 0) {
xon = 1;
xPos = 0;
}
if (xPos >= (width - Woffset)) {
xon = 0;
xPos = (width - Woffset);
}
}
function start() {
img.visibility = "visible";
interval = setInterval('changePos()', delay);
}
start();
</SCRIPT>
