document.body.scrollTop为零,解决方法一:
把DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" 改为:
DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" " 即可;
方法二:
var scrollPos;
if ( typeof window.pageYOffset != ' undefined ' ) {
scrollPos = window.pageYOffset;
}
else if ( typeof document.compatMode != ' undefined ' &&
document.compatMode != ' BackCompat ' ) {
scrollPos = document.documentElement.scrollTop;
}
else if ( typeof document.body != ' undefined ' ) {
scrollPos = document.body.scrollTop;
}
alert(scrollPos);
if ( typeof window.pageYOffset != ' undefined ' ) {
scrollPos = window.pageYOffset;
}
else if ( typeof document.compatMode != ' undefined ' &&
document.compatMode != ' BackCompat ' ) {
scrollPos = document.documentElement.scrollTop;
}
else if ( typeof document.body != ' undefined ' ) {
scrollPos = document.body.scrollTop;
}
alert(scrollPos);
例如:


body部分
<div id="div1" style="width:150px; height:150px; background-color:#000066; position:absolute; top:0px; right:0px;"></div>
<div id="one" style="width:700px; height:1000px; border:1px solid red;"></div>
javascript 部分
window.onscroll=function(){
var oDiv=document.getElementById("div1");
var scrollPos;
if (typeof window.pageYOffset != 'undefined') {
scrollPos = window.pageYOffset;
}
else if (typeof document.compatMode != 'undefined' &&
document.compatMode != 'BackCompat') {
scrollPos = document.documentElement.scrollTop;
}
else if (typeof document.body != 'undefined') {
scrollPos = document.body.scrollTop;
}
// alert(document.body.clientWidth);
// alert(document.body.clientWidth);
// alert(document.body.scrollWidth);
oDiv.style.top=scrollPos+"px";
// oDiv.style.left =document.documentElement.scrollLeft+"px";