js获取鼠标位置

<h3>您的鼠标已经被跟踪</h3>
<p> X 轴坐标：<span id="x"></span></p>
<p> Y 轴坐标：<span id="y"></span></p>

function mousePosition(ev){
        if(ev.pageX || ev.pageY){//firefox、chrome等浏览器
            return {x:ev.pageX,y:ev.pageY};
        }
        return {// IE浏览器
            x:ev.clientX + document.body.scrollLeft - document.body.clientLeft,
            y:ev.clientY + document.body.scrollTop - document.body.clientTop
        };
    }

function mouseMove(ev){
        ev = ev || window.event;
        var mousePos = mousePosition(ev);
        document.getElementById('x').innerHTML = mousePos.x;
        document.getElementById('y').innerHTML = mousePos.y;
}

document.onmousemove = mouseMove;