移动图片会出现抖动现象

用capture捕获。看例子<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> how to make a drag division - http://www.never-online.net </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="never-online, blueDestiny">
<META NAME="Keywords" CONTENT="never-online, blueDestiny">
<META NAME="Description" CONTENT="http://www.never-online.net">
<style>
<!--
body {
font-size:0.9em;
font-family:verdana;
background-color:appworkspace;
}
.myDiv {
border:4px solid #006699;
height:200px;
width:400px;
color:#003399;
padding:20px;
font-weight:bolder;
text-align:center;
background-color:#eeeeee;
}
.copyright
{
text-align: center;
font-size: 1em;
}
-->
</style>
<SCRIPT LANGUAGE="JavaScript">
<!--function neverDragDivision(fObj) { with (this)
{
if (!fObj) return;
this.bDraged = false;
this.oDragOrig = fObj;
oDragOrig.style.cursor = "move";
oDragOrig.onmousedown = function()
{
var ofs = Offset(oDragOrig);
    oDragOrig.style.position = "absolute";
oDragOrig.style.left = ofs.l;
oDragOrig.style.top = ofs.t;
oDragOrig.X = event.clientX - ofs.l;
oDragOrig.Y = event.clientY - ofs.t;
bDraged = true;
};
oDragOrig.onmousemove = function()
{
if (!bDraged) return;
    oDragOrig.setCapture();
oDragOrig.style.left = event.clientX - oDragOrig.X;
oDragOrig.style.top = event.clientY - oDragOrig.Y; };
oDragOrig.onmouseup = function()
{
bDraged = false;
oDragOrig.releaseCapture();
};
function Offset(e) {
var t = e.offsetTop;
var l = e.offsetLeft;
var w = e.offsetWidth;
var h = e.offsetHeight;
while(e=e.offsetParent) {
t+=e.offsetTop;
l+=e.offsetLeft;
}
return { t:t, l:l, w:w, h:h }
};
}};//-->
</SCRIPT>
</HEAD>
<BODY>
<table>
<tr>
<td>
<div class="myDiv">
http://www.never-online.net
<p>power by blueDestiny, never-online</p>
</div>
</td>
<td>
<div class="myDiv" style="width:450px">
<p>never-online, Everlasting love for angela.</p>
</div>
</td>
</tr>
</table>
<h4 class="copyright"> Power By blueDestiny, never-online, <a href="http://www.never-online.net" _fcksavedurl="http://www.never-online.net">http://www.never-online.net</a> </h4>
<SCRIPT LANGUAGE="JavaScript">
<!--
var aDivs = document.getElementsByTagName("DIV");
for (var i=0; i<aDivs.length; i++) {
new neverDragDivision(aDivs[i]);
}
//-->
</SCRIPT>
</BODY>
</HTML>