document.onclick=function(event){
var e=event?event:window.event;
var ee=e.target||e.srcElement;
alert(ee.tagName);

}

document.onkeydown=function(event){
//alert(event);
//var e=event||window.event;
//alert(e);
var e =event?event:window.event;
if(e.keyCode==13){
alert("hello");
alert(e.target||e.srcElement);
}


}

//鼠标坐标

var he=document.getElementById("he");
alert(he.innerHTML);
document.onmousemove=function(e){
var e=event?event:window.event;
he.innerHTML=e.clientX+" "+e.clientY;
}

e.target与e.e.srcElement