js+css使DIV始终居于屏幕中间 左下 左上 右上 右下的代码集合

代码如下:

<!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/
<!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>随滚动条移动的层 </TITLE>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html" charset="gb2312">
</HEAD>
<style>
<!--
.div{
position: absolute;
border: 2px solid red;
background-color: #EFEFEF;
line-height:90px;
font-size:12px;
z-index:1000;
}
-->
</style>
<BODY>
<div id="Javascript.Div1" class="div" style="width: 240px; height:90px" align="center">正中...</div>
<SCRIPT LANGUAGE="JavaScript">
function sc1(){
document.getElementById("Javascript.Div1").style.top=(document.documentElement.scrollTop+(document.documentElement.clientHeight-document.getElementById("Javascript.Div1").offsetHeight)/2)+"px";
document.getElementById("Javascript.Div1").style.left=(document.documentElement.scrollLeft+(document.documentElement.clientWidth-document.getElementById("Javascript.Div1").offsetWidth)/2)+"px";
}
</SCRIPT>
<div id="Javascript.Div2" class="div" style="width: 240px; height:90px" align="center">左上...</div>
<SCRIPT LANGUAGE="JavaScript">
function sc2(){
document.getElementById("Javascript.Div2").style.top=(document.documentElement.scrollTop)+"px";
document.getElementById("Javascript.Div2").style.left=(document.documentElement.scrollLeft)+"px";
}
</SCRIPT>

<div id="Javascript.Div3" class="div" style="width: 240px; height:90px" align="center">左下...</div>
<SCRIPT LANGUAGE="JavaScript">
function sc3(){
document.getElementById("Javascript.Div3").style.top=(document.documentElement.scrollTop+document.documentElement.clientHeight-document.getElementById("Javascript.Div3").offsetHeight)+"px";
document.getElementById("Javascript.Div3").style.left=(document.documentElement.scrollLeft)+"px";
}
</SCRIPT>

<div id="Javascript.Div4" class="div" style="width: 240px; height:90px" align="center">右上...</div>
<SCRIPT LANGUAGE="JavaScript">
function sc4(){
document.getElementById("Javascript.Div4").style.top=(document.documentElement.scrollTop)+"px";
document.getElementById("Javascript.Div4").style.left=(document.documentElement.scrollLeft+document.documentElement.clientWidth-document.getElementById("Javascript.Div4").offsetWidth)+"px";
}
</SCRIPT>

<div id="Javascript.Div5" class="div" style="width: 240px; height:90px" align="center">右下...</div>
<SCRIPT LANGUAGE="JavaScript">
function sc5(){
document.getElementById("Javascript.Div5").style.top=(document.documentElement.scrollTop+document.documentElement.clientHeight-document.getElementById("Javascript.Div5").offsetHeight)+"px";
document.getElementById("Javascript.Div5").style.left=(document.documentElement.scrollLeft+document.documentElement.clientWidth-document.getElementById("Javascript.Div5").offsetWidth)+"px";
}
</SCRIPT>

<SCRIPT LANGUAGE="JavaScript">
<!--
function scall(){
sc1();sc2();sc3();sc4();sc5();
}
window.onscroll=scall;
window.onresize=scall;
window.onload=scall;
//-->
</SCRIPT>
<div style="position: absolute; top: 0px; left: 0px; width: 10000px; height: 4000px;"></div>
</BODY>
</HTML>