IE和FF下获取鼠标当前位置

IE:

JS: function test_event() {
       var x = event.clientX + document.body.scrollLeft;
       var y = event.clientY + document.body.scrollTop;
       alert("左边:"+x+ ", 右边:"+y);
}
HTML: <span onclick="test_event();">click me</span>

 

FF:

JS: function test_event(event) {
       var x = event.clientX + document.body.scrollLeft;
       var y = event.clientY + document.body.scrollTop;
       alert("左边:"+x+ ", 右边:"+y);
}
HTML: <span onclick="test_event(event);">click me</span>