自定义对象与dom对象合并

<script type="text/javascript">
function Obj(o){
	o = document.getElementById(o);
	var me = this;
	for(var key in me){
		o[key] = me[key];
	}
	return o;
}

Obj.prototype.say = function(){
	//注意 这里的this是dom对象了
	alert(this.innerHTML);
}
window.onload =function(){
	//注意这里一定要用new
	var o = new Obj("btn");
	o.onclick=function(){
		alert(this.say);
	}
	
	o.say();
}

</script>
<button id="btn">点击俺</button>