div js拖拽

/**
* js拖拽div类
* -----------------------------
* DEMO:<script type="text/javascript" src="drag.js"></script> 
* <div id="divAlert" onMouseDown="catchFlyBar(event, this)" onMouseUp="releaseFlyBar()" style='position:absolute;top:100px;left:200px;cursor:move;z-index:100;' />
* -----------------------------
*/
function getElement() {
    var elements = new Array();
    for (var i = 0; i < arguments.length; i++) {
        var element = arguments[i];
        if (typeof element == 'string')
          element = document.getElementById(element);
        if (arguments.length == 1)
          return element;
        elements.push(element);
    }
    return elements;
}

var isIE=(navigator.appVersion.indexOf("MSIE")!=-1)?true:false;
//var bIsCatchFlyBar = false;
var dragClickX = 0;
var dragClickY = 0;
var dragDivObj;
function catchFlyBar(ev, divObj){
    ev=ev||window.event;
    //bIsCatchFlyBar = true;

    var x=ev.clientX+document.body.scrollLeft;
    var y=ev.clientY+document.body.scrollTop;
    //divObj = getElement("divAlert");    
    dragDivObj = divObj;
    dragClickX=x-parseInt(dragDivObj.style.left);
    dragClickY=y-parseInt(dragDivObj.style.top);
    isIE? dragDivObj.setCapture():null;
    document.onmousemove = moveFlyBar;
}

function moveFlyBar(ev){
    ev=ev||window.event;
    //if(bIsCatchFlyBar){
        dragDivObj.style.left = ev.clientX-dragClickX+"px";
        dragDivObj.style.top = ev.clientY-dragClickY+"px";
        //getElement("xx").innerHTML=dragDivObj.style.left;
        //getElement("yy").innerHTML=dragDivObj.style.left;
    //}
}

function releaseFlyBar(){
    //bIsCatchFlyBar = false;
    isIE? dragDivObj.releaseCapture():null;
    document.onmousemove = null;
}