var x,y,z,down=false,obj
function init(){
obj=event.srcElement //事件觸發(fā)對(duì)象
obj.setCapture() //設(shè)置屬于當(dāng)前對(duì)象的鼠標(biāo)捕捉
z=obj.style.zIndex //獲取對(duì)象的z軸坐標(biāo)值
//設(shè)置對(duì)象的z軸坐標(biāo)值為100，確保當(dāng)前層顯示在最前面
obj.style.zIndex=100
x=event.offsetX //獲取鼠標(biāo)指針位置相對(duì)于觸發(fā)事件的對(duì)象的X坐標(biāo)
y=event.offsetY //獲取鼠標(biāo)指針位置相對(duì)于觸發(fā)事件的對(duì)象的Y坐標(biāo)
down=true //布爾值，判斷鼠標(biāo)是否已按下，true為按下，false為未按下
}
function moveit(){
//判斷鼠標(biāo)已被按下且onmouseover和onmousedown事件發(fā)生在同一對(duì)象上
if(down&&event.srcElement==obj){
with(obj.style){
/*設(shè)置對(duì)象的X坐標(biāo)值為文檔在X軸方向上的滾動(dòng)距離加上當(dāng)前鼠標(biāo)指針相當(dāng)于文檔對(duì)象的X坐標(biāo)值減鼠標(biāo)按下時(shí)指針位置相對(duì)于觸發(fā)事件的對(duì)象的X坐標(biāo)*/
// posLeft=event.x-x;
posLeft=document.body.scrollLeft+event.x-x;
/*設(shè)置對(duì)象的Y坐標(biāo)值為文檔在Y軸方向上的滾動(dòng)距離加上當(dāng)前鼠標(biāo)指針相當(dāng)于文檔對(duì)象的Y坐標(biāo)值減鼠標(biāo)按下時(shí)指針位置相對(duì)于觸發(fā)事件的對(duì)象的Y坐標(biāo)*/
// posTop=event.y-y;
posTop=document.body.scrollTop+event.y-y;
window.status="posLeft="+posLeft+",posTop="+posTop;
window.status=window.status+"clientX="+event.clientX+"clientY="+event.clientY+"scrollLeft="+document.body.scrollLeft+"scrollTop="+document.body.scrollTop+",event.y="+event.y+",event.x"+event.x;
}
}
}
function stopdrag(){
//onmouseup事件觸發(fā)時(shí)說(shuō)明鼠標(biāo)已經(jīng)松開(kāi)，所以設(shè)置down變量值為false
down=false
obj.style.zIndex=z //還原對(duì)象的Z軸坐標(biāo)值
obj.releaseCapture() //釋放當(dāng)前對(duì)象的鼠標(biāo)捕捉
//alert("X:"+obj.style.left+";Y:"+obj.style.top);
}

<div id="t" style="position:relative;top:0px;left:0px;"> </div>

<div id="t" style="position:relative;top:0px;left:0px;">
<div id="tt" style="position:absolute;top:9px;left:317px;">
<IMG id="hong" SRC="main/1.jpg" WIDTH="8" HEIGHT="8" BORDER="0"
ALT="" />
</div>
<div >省略</div>
<div >省略</div>
<div >省略</div>
<div >省略</div>
<div >省略</div>
<div >省略</div>
<div >省略</div>
<div >省略</div>
<div >省略</div>

<div onmousedown=init() onmousemove=moveit()
onmouseup=stopdrag()
style="position:absolute;left:60;top:190;width:5;height:5;z-index:99;;border:1px solid #000000;">
D
</div>
</div>