IE8上窗口拖动效果，总感觉抖动得厉害

IE8下窗口拖动效果，总感觉抖动得厉害
本帖最后由 business122 于 2012-12-18 16:30:23 编辑 是这样的，先前用JQuery UI里的draggable实现弹出窗口的拖动效果感觉在IE8下感觉有些抖动，后来自己写了代码实现效果还是有这个问题，不知道各位大哥们有没有遇到过类似的问题。代码如下：
$newWin.draggable{(
  handle: 'div.win_title'
  iframeFix: false,
  scroll: false
)}

自己后来写的：
  function Do_WinChange(minWidth, minHeight) {
            var dragging = false;
            var resizing = false;
            var iX, iY;
            var w, h;
            var l, t;

            $("#myWin_welcome").mousedown(function (e) {
                w = parseInt($("#myWin_welcome").css("width"));
                h = parseInt($("#myWin_welcome").css("height"));

                l = $("#myWin_welcome").offset().left;
                t = $("#myWin_welcome").offset().top;
                iX = e.clientX - l;
                iY = e.clientY - t;

                if (w - iX < 12 || h - iY < 12) {
                    resizing = true; ; //伸缩窗口
                }
                else {
                    dragging = true;
                }

                this.setCapture && this.setCapture();
                return false;
            });

            document.onmousemove = function (e) {
                var e = e || window.event; //获取事件
                if (dragging) {
                    var oX = e.clientX - iX;
                    var oY = e.clientY - iY;
                    $("#myWin_welcome").css({ "left": oX + "px", "top": oY + "px" });

                    return false;
                }
                if (resizing) {
                    _w = Math.max(e.clientX - l, minWidth);
                    _h = Math.max(e.clientY - t, minHeight);
                    $("#myWin_welcome").css({ "width": _w + 'px', "height": _h + 'px' });
                    $("#myFrame_myWin_welcome").css({ "width": _w + 'px', "height": _h + 'px' });
                    return false;
                }
            }

            document.onmouseup = function (e) {
                var e = e || window.event;
                dragging = false; //移动停止
                resizing = false; //停止伸缩
                //                $("#main").animate({ "left": _offset.left + "px", "top": _offset.top + "px" }, 400)//返回原处

                $("#myWin_welcome").releaseCapture();

                if (e.stopPropagation) {
                    e.stopPropagation();
                }
                else {
                    e.cancelBubble = true;
                }
                if (e.preventDefault) {
                    e.preventDefault();
                }
                else {
                    e.returnValue = false;
                }

            }
        }

大婶们！求围观！！可加分！！
[解决办法]

<div id="f" style="position: absolute; width: 200px; height: 150px; background-color: #ccc; top: 150px; left: 200px; z-index: 101; border: solid 1px blue;">
    <div id="title" style="background-color: Blue; cursor: move; height: 20px; color: #fff;font-size: 13px; padding-top: 5px; padding-left: 10px;"> 拖动层 </div>
</div>
<script type="text/javascript">
    var $=function (id){
        var II=document.getElementById(id);
        if(!II){
            alert(id+" 控制对象不存在！") ;
            return false;
        }else{
            return document.getElementById(id);
        }
    }
    var posX,posY;
    var fdiv = $("f");
    $("title").onmousedown=function(e)
    {
        if(!e) e = window.event;
        posX = e.clientX - parseInt(fdiv.style.left);
        posY = e.clientY - parseInt(fdiv.style.top);
        document.onmousemove = mousemove;
    }
    document.onmouseup = function(){document.onmousemove = null;}
    function mousemove(ev)
    {
        if(ev==null) ev = window.event;
        fdiv.style.left = (ev.clientX - posX) + "px";
        fdiv.style.top = (ev.clientY - posY) + "px";
    }
</script>