一个很酷的拖动层的js类，兼容IE及Firefox

自己优化修改了网上的一个JS拖动类，增加了拖动时显示半透明的特效。 http://www.jb51.net/article/16122.htm
注意，本文类中的Cminfo类请 查看：
http://www.jb51.net/article/18760.htm

代码如下:

//*********************************移动层 函数 开始*******************************************
//生成拖动层很简单,只需要(参数之一如果是数组表示局部拖动,arr[0]表示拖动层,arr[1]表示整体)
//new divDrag(['test'], [getObject('test31'),getObject('test3')], getObject('test1') ,getObject('test2') ,[getObject('test41'),getObject('test4')]);
//记得有拖动属性的层position:absolute;
Array.prototype.extend = function(C){for(var B=0,A=C.length;B<A;B++){this.push(C[B]);}return this;}
function divDrag()
{
    var A,B,gCn;
    var zIndex = 1;
    this.dragStart = function(e)
    {
        e = e||window.event;
        if((e.which && (e.which!=1))||(e.button && (e.button!=1))){return;}
        var pos = this.gPos;
        gCn = this.parent||this;
        if(document.defaultView)
        {
            _top = document.defaultView.getComputedStyle(gCn,null).getPropertyValue("top");
            _left = document.defaultView.getComputedStyle(gCn,null).getPropertyValue("left");
        }
        else
        {
            if(gCn.currentStyle)
            {
                _top = gCn.currentStyle["top"];
                _left = gCn.currentStyle["left"];
            }
        }
        pos.ox = (e.pageX||(e.clientX+document.documentElement.scrollLeft))-parseInt(_left);
        pos.oy = (e.pageY||(e.clientY+document.documentElement.scrollTop))-parseInt(_top);
        if(!!A)
        {
            if(document.removeEventListener)
            {
                document.removeEventListener("mousemove",A,false);
                document.removeEventListener("mouseup",B,false);
            }
            else
            {
                document.detachEvent("onmousemove",A);
                document.detachEvent("onmouseup",B);
            }
        }
        A = this.dragMove.create(this);
        B = this.dragEnd.create(this);
        if(document.addEventListener)
        {
            document.addEventListener("mousemove",A,false);
            document.addEventListener("mouseup",B,false);
        }
        else
        {
            document.attachEvent("onmousemove",A);
            document.attachEvent("onmouseup",B);
        }
        gCn.style.zIndex = (++zIndex);
    }
    this.dragMove = function(e)
    {
        e = e||window.event;
        var pos = this.gPos;
        gCn = this.parent||this;
        gCn.style.top = (e.pageY||(e.clientY+document.documentElement.scrollTop))-parseInt(pos.oy)+'px';
        gCn.style.left = (e.pageX||(e.clientX+document.documentElement.scrollLeft))-parseInt(pos.ox)+'px';
        try{if(CMInfo.Bs_Name=='IE'){gCn.style.filter = "alpha(opacity=70)";}else{gCn.style.opacity = "0.7";}}catch(e){}
        this.stop(e);
    }
    this.dragEnd = function(e)
    {
        var pos = this.gPos;
        e = e||window.event;
        if((e.which && (e.which!=1))||(e.button && (e.button!=1))){return};
        gCn = this.parent||this;
        if(!!(this.parent)){this.style.backgroundColor = pos.color;}
        try{if(CMInfo.Bs_Name=='IE'){gCn.style.filter = "alpha(opacity=100)";}else{gCn.style.opacity = 1;}}catch(e){}
        if(document.removeEventListener)
        {
            document.removeEventListener("mousemove",A,false);
            document.removeEventListener("mouseup",B,false);
        }
        else
        {
            document.detachEvent("onmousemove",A);
            document.detachEvent("onmouseup",B);
        }
        A = null;
        B = null;
        gCn.style.zIndex = (++zIndex);
        this.stop(e);
    }
    this.shiftColor = function()
    {
        this.style.backgroundColor="#EEEEEE";                                    
    }
    this.position = function (e)
    {
        var t=e.offsetTop;
        var l=e.offsetLeft;
        while(e=e.offsetParent)
        {
            t += e.offsetTop;
            l += e.offsetLeft;
        }
        return {x:l,y:t,ox:0,oy:0,color:null}
    }
    this.stop = function(e)
    {
        if(e.stopPropagation){e.stopPropagation();}else{e.cancelBubble=true;}
        if(e.preventDefault){e.preventDefault();}else{e.returnValue=false;}
    }
    this.create = function(bind)
    {
        var B = this;
        var A = bind;
        return function(e){return B.apply(A,[e]);}
    }
    this.dragStart.create = this.create;
    this.dragMove.create = this.create;
    this.dragEnd.create = this.create;
    this.shiftColor.create = this.create;
    this.initialize = function()
    {
        for(var A=0,B=arguments.length;A<B;A++)
        {
            C=arguments[A];
            if(!(C.push)){C = [C];}
            gC = (typeof(C[0])=='object')?C[0]:(typeof(C[0])=='string'?getObject(C[0]):null);
            if(!gC){continue};
            gC.gPos = this.position(gC);
            gC.dragMove = this.dragMove;
            gC.dragEnd = this.dragEnd;
            gC.stop = this.stop;
            if(!!C[1])
            {
                gC.parent = C[1];
                gC.gPos.color = gC.style.backgroundColor;
            }
            if(gC.addEventListener)
            {
                gC.addEventListener("mousedown",this.dragStart.create(gC),false);
                if(!!C[1]){gC.addEventListener("mousedown",this.shiftColor.create(gC),false);    }
            }
            else
            {
                gC.attachEvent("onmousedown",this.dragStart.create(gC));
                if(!!C[1]){gC.attachEvent("onmousedown",this.shiftColor.create(gC));}
            }
        }
    }
    this.initialize.apply(this,arguments);
}
//*********************************移动层 函数 结束*******************************************