基于层的网页弹出提示，可移动，网页变灰

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>基于层的网页弹出提示，可移动，网页变灰－/</title>
<style type="text/css">

</style>
</head>
<body >
<div ;
}
}

    /*-------------------------鼠标拖动---------------------*/
    var od = document.getElementById("fd");
    var dx,dy,mx,my,mouseD;
    var odrag;
    var isIE = document.all ? true : false;
    document.onmousedown = function(e){
        var e = e ? e : event;
        if(e.button == (document.all ? 1 : 0))
        {
            mouseD = true;
        }
    }
    document.onmouseup = function(){
        mouseD = false;
        odrag = "";
        if(isIE)
        {
            od.releaseCapture();
            od.filters.alpha.opacity = 100;
        }
        else
        {
            window.releaseEvents(od.MOUSEMOVE);
            od.style.opacity = 1;
        }
    }

    //function readyMove(e){
    od.onmousedown = function(e){
        odrag = this;
        var e = e ? e : event;
        if(e.button == (document.all ? 1 : 0))
        {
            mx = e.clientX;
            my = e.clientY;
            od.style.left = od.offsetLeft + "px";
            od.style.top = od.offsetTop + "px";
            if(isIE)
            {
                od.setCapture();
                od.filters.alpha.opacity = 50;
            }
            else
            {
                window.captureEvents(Event.MOUSEMOVE);
                od.style.opacity = 0.5;
            }

            //alert(mx);
            //alert(my);

        }
    }
    document.onmousemove = function(e){
        var e = e ? e : event;

        //alert(mrx);
        //alert(e.button);
        if(mouseD==true && odrag)
        {
            var mrx = e.clientX - mx;
            var mry = e.clientY - my;
            od.style.left = parseInt(od.style.left) +mrx + "px";
            od.style.top = parseInt(od.style.top) + mry + "px";
            mx = e.clientX;
            my = e.clientY;

        }
    }
function showBackground(obj,endInt)
{
obj.filters.alpha.opacity+=1;
if(obj.filters.alpha.opacity<endInt)
{
setTimeout(function(){showBackground(obj,endInt)},8);
}
}
</script>
</body>
</html>