比较精简的Javascript拖动效果函数代码

<html>  
<head><title>拖动效果函数演示 by Longbill.cn</title>  
<style>  
body   
{  
    font-size:12px;  
    color:#333333;  
    border : 0px solid blue;  
}  
div  
{  
    position : absolute;  
    background-color : #c3d9ff;  
    margin : 0px;  
    padding : 5px;  
    border : 0px;  
    width : 100px;  
    height:100px;  
}  
</style>  
</head>  
<body>  
<script>  
function drag(o,s)  
{  
    if (typeof o == "string") o = document.getElementById(o);  
    o.orig_x = parseInt(o.style.left) - document.body.scrollLeft;  
    o.orig_y = parseInt(o.style.top) - document.body.scrollTop;  
    o.orig_index = o.style.zIndex;  
          
    o.onmousedown = function(a)  
    {  
        this.style.cursor = "move";  
        this.style.zIndex = 10000;  
        var d=document;  
        if(!a)a=window.event;  
        var x = a.clientX+d.body.scrollLeft-o.offsetLeft;  
        var y = a.clientY+d.body.scrollTop-o.offsetTop;  
        //author: www.longbill.cn  
        d.ondragstart = "return false;"  
        d.onselectstart = "return false;"  
        d.onselect = "document.selection.empty();"  
                  
        if(o.setCapture)  
            o.setCapture();  
        else if(window.captureEvents)  
            window.captureEvents(Event.MOUSEMOVE|Event.MOUSEUP);

d.onmousemove = function(a)  
        {  
            if(!a)a=window.event;  
            o.style.left = a.clientX+document.body.scrollLeft-x;  
            o.style.top = a.clientY+document.body.scrollTop-y;  
            o.orig_x = parseInt(o.style.left) - document.body.scrollLeft;  
            o.orig_y = parseInt(o.style.top) - document.body.scrollTop;  
        }

d.onmouseup = function()  
        {  
            if(o.releaseCapture)  
                o.releaseCapture();  
            else if(window.captureEvents)  
                window.captureEvents(Event.MOUSEMOVE|Event.MOUSEUP);  
            d.onmousemove = null;  
            d.onmouseup = null;  
            d.ondragstart = null;  
            d.onselectstart = null;  
            d.onselect = null;  
            o.style.cursor = "normal";  
            o.style.zIndex = o.orig_index;  
        }  
    }  
      
    if (s)  
    {  
        var orig_scroll = window.onscroll?window.onscroll:function (){};  
        window.onscroll = function ()  
        {  
            orig_scroll();  
            o.style.left = o.orig_x + document.body.scrollLeft;  
            o.style.top = o.orig_y + document.body.scrollTop;  
        }  
    }  
}  
</ script>

<div id="div1" style="left:10px;top:10px;">div1:我可以被拖动</div>  
<div id="div2" style="left:120px;top:10px;background-color : #f3d9ff">div2:来拖我呀</div>  
<div id="div3" style="left:230px;top:10px;background-color : #c3ffff">div3:我随便你拖</div>  
<div id="div4" style="left:10px;top:120px;background-color : #c3d944">div4:我可以随窗口滑动，把我拖到最下面，然后滚动网页看看</div>  
<div id="div5" style="left:120px;top:120px;background-color : #f3d944">作者: Longbill
www.longbill.cn  
</div>  
<div id="div6" style="left:230px;top:120px;background-color : #e3f944;width:200px;">参数说明:
  
drag(obj [,scroll]);
  
obj:对象的id或对象本身;
  
scroll(可选):对象是否随窗口拖动而滑动，默认为否
  
鼠标右键查看源代码  
</div>

</ script>

</body>

[Ctrl+A 全选注:如需引入外部Js需刷新才能执行]

比较精简的Javascript拖动效果函数代码_javascript技巧