获取鼠标在屏幕上的位置

function mousePosition(ev){
    if(ev.pageX || ev.pageY){
            return {x:ev.pageX, y:ev.pageY};
        }
            return {
                x:ev.clientX + document.body.scrollLeft - document.body.clientLeft,
                y:ev.clientY + document.body.scrollTop  - document.body.clientTop
        };
} 

 

使用方法：

 

document.onmousemove = mouseMove;

function mouseMove(ev){
    ev = ev || window.event; //定义一个ev对象
    var mousePos = mousePosition(ev);

	document.getElementById('mouseXPosition').value = mousePos.x;
	document.getElementById('mouseYPosition').value = mousePos.y;
}